Method of designing and positioning a medical implant and an implant comprising a positioning mark

ABSTRACT

The present invention relates to a method for designing an implant comprising designing a contour curvature of the implant so that an articulating surface of the implant is designed to correspond to a simulated healthy articulating surface of a damaged articulating surface of a joint. The implant is provided with at least one positioning mark designed to be used for determining the orientation in which the implant is to be placed in a recess made in a damaged articulating surface of a joint. Further, the present invention relates to methods for positioning and inserting a medical implant in a recess.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of co-pending prior U.S.patent application Ser. No. 16/148,134, filed Oct. 1, 2018, which is adivisional application of co-pending prior U.S. patent application Ser.No. 14/784,376, filed Oct. 14, 2015, now U.S. Pat. No. 10,143,556,issued Dec. 4, 2018, which is the National Stage of InternationalApplication No. PCT/EP2013/057847, filed Apr. 15, 2013. The contents ofeach of these applications are incorporated herein in their entirety.

FIELD OF THE INVENTION

This invention relates in general to the field of designing tools foruse during replacement of damaged cartilage in an articulating surfacein a joint all comprising positioning marks. The present invention alsoconfers to tools made using the design method according to the inventionand methods for rotationally positioning and inserting a medical implantin a recess.

BACKGROUND General Background

Pain and overuse disorders of the joints in the body is a commonproblem. The weight-bearing and articulating surfaces of the knees, andof other joints, are covered with a layer of soft tissue that typicallycomprises a significant amount of hyaline cartilage. The frictionbetween the cartilage and the surrounding parts of the joint is verylow, which facilitates movement of the joints under high pressure. Thecartilage is however prone to damage due to disease, injury or chronicwear. Moreover it does not readily heal after damages, as opposed toother connective tissue, and if healed the durable hyaline cartilage isoften replaced by less durable fibrocartilage. This means that damagesof the cartilage gradually become worse. Along with injury/disease comesa problem with pain which results in handicap and loss of function. Itis therefore important to have efficient means and methods for repairingdamaged cartilage in knee joints.

The advantages of implants have stimulated a further development ofsmaller implants that can be implanted with less invasive surgery. Inthis development there has also been an effort to achieve small jointimplants, suitable for repair of a small cartilage injury that have aminimal influence on the surrounding parts of the joint. In the surgicaloperation of implanting such small implants it is critical that theimplant is positioned in a precise manner. If the implant is offset fromits intended position it may cause an increased wear or load on thejoint. For example, if the implant is tilted this may result in an edgethat projects above the cartilage surface and causes wear on theopposing cartilage in the joint. Another example is the case that theimplant is placed in a too shallow position, which may result in a toohigh top of the implant that causes the joint to articulate in an unevenmanner and increase the load on an opposing point of the joint. For thepatient, also small misplacements or deviations from an ideal positionmay result in pain, longer time for convalescence or even a surgicaloperation being done in vain and making it more difficult to repair thedamage in the joint. A large burden is therefore placed on the surgeonnot to misplace or misfit the implant. There is therefore a need forwell fitting implants as well as tools that are designed to relieve andsupport the surgeon in the implant surgery.

Specific Background

The design of the implant and the surgical tools, in other words, thedesign of the surgical kit is crucial for the outcome of the implantslife-time in a joint. Also, the parameters for designing are ofuttermost importance for the result in these operations. Smalldifferences in the design can make a huge difference in fit andlife-time of an implant in the body, convalescence time for the patient,economic values due to surgery time, success of operations, also thenumber of successful operations will increase and the working conditionsfor the surgeon will be improved if the designing parameters areselected right etc.

There is a need for a design method for a guide for use during repair ofa cartilage damage which is more user friendly for the surgeon than theguide tools known from prior art. There is a need for a guide tool whichallows for small surgical cuts and also a design method which allows forproducing small guide tools which still are stable and easy to use forthe surgeon allowing for precise insertion of implants in a joint.

PRIOR ART

A prior art document which describe the design of an orthopedic implantsand corresponding tools is for example:

EP2389905 A1 shows a design method for designing an individuallydesigned surgical kit.

OBJECT OF THE INVENTION

The general object of the invention is to solve the problem of designingan improved guide tool for use during cartilage repair for replacingdamaged cartilage and also an improved design method for designinginserts tools and also implants. The design of the guide tool and theinsert tools and the implant makes the surgical operation safer andresults in better fitting implants, less surgeon dependent operationprocedures and faster recovery of the patients after surgery due to thatthe implant guide can be made smaller and neater using this designmethod. It is a further object of the invention to provide a solutionfor making the surgical operation of rotationally positioning andinserting an implant in a recess safer and more accurate by providing apositioning mark on the implant which is adapted for rotationallypositioning the implant in the recess.

SUMMARY OF THE INVENTION

The object of the invention is achieved with a system for designing aguide tool and/or a surgical kit and or an implant.

The present invention relates to a method for designing an implant,comprising:

-   -   designing a contour curvature of the implant so that an        articulating surface of the implant is designed to correspond to        a simulated healthy articulating surface of a damaged        articulating surface of a joint;    -   providing at least two substantially circular shapes such that        each of said substantially circular shapes is partly overlapping        at least one other substantially circular shape; and    -   providing at least one positioning mark on at least one of said        at least two substantially circular shapes such that said at        least one positioning mark is designed to be used for        determining the orientation in which the implant is to be placed        in a recess made in a damaged articulating surface of a joint.

The present invention also relates to a method for inserting an implantin a joint, comprising:

-   -   providing an implant having at least one positioning mark,        wherein said at least one positioning mark is positionally        adapted on the surface of the implant to be visible for        detection by a vision system;    -   detecting, by the vision system, said at least one positioning        mark in relation to at least one of at least one mark made on        the side of a recess made in the articulating surface of the        joint and at least one pre-determined anatomic dependent        direction; and    -   inserting the implant in the recess by directing the at least        one implant positioning mark in a direction dependent on the        direction of at least one of at least one mark made on the side        of a recess made in the articulating surface of the joint and at        least one pre-determined anatomic dependent direction, wherein        said inserting is aided by said detecting by the vision system.

The present invention further relates to a method for inserting animplant in a joint, comprising:

-   -   providing an implant having at least one positioning mark,        wherein said at least one positioning mark is located on the        surface of the implant to be visible for detection;    -   providing a storage unit, e.g. a box, for storing an implant        prior to inserting the implant in a recess of a human joint,        wherein said storage unit comprises at least one of a mechanical        recess structure and/or holding means adapted for positioning        the implant in a rotationally fixed position in the storage        unit, and wherein said storage unit further comprises at least        one reference feature;    -   detecting said at least one positioning mark in relation to said        at least one reference feature;    -   placing the implant in the storage unit by directing the at        least one implant positioning mark on the surface of the implant        in a specific, e.g. pre-determined, rotational direction in        relation to said at least one reference feature of the storage        unit;    -   gripping the implant in the storage unit, wherein the implant is        rotationally oriented in accordance with said specific        rotational direction of the at least one implant positioning        mark in relation to said at least one reference feature of the        storage unit;    -   removing the implant from the storage unit, wherein the implant        is rotationally oriented in accordance with said specific        rotational direction of the at least one implant positioning        mark in relation to said at least one reference feature of the        storage unit when removed from the storage unit; and    -   inserting the implant in a recess made in a human joint in a        correct placement orientation, wherein said correct placement        orientation is determined by how the implant is rotationally        positioned in said storage unit in relation to said at least one        reference feature of the storage unit.

The present invention further relates to a medical implant comprising atleast two substantially circular shapes where each of said substantiallycircular shapes is partly overlapping at least one other circular shape,and where at least one of the at least two substantially circular shapesis provided with at least one positioning mark on its surface.

In embodiments, the technology disclosed relates to a medical implantcomprising at least two substantially circular shapes such that each ofsaid circular shapes is partly overlapping at least one other circularshape, and wherein at least one of the at least substantially circularshapes is provided with at least one positioning mark on its surface,wherein the positioning mark is designed to be used for determining theorientation in which the implant is to be placed in a recess made in ajoint.

In certain embodiments, the technology disclosed relates to a method fordesigning an implant, comprising:

-   -   designing the shape and size of the implant dependent on the        size and shape of the damage in the articulating surface and        dependent on the curvature of the simulated healthy contour of        the articulating surface in the area substantially coinciding        with the damage; and    -   designing the positioning mark to point out the same direction,        or joint axis, as at least one of a mark made, or to be made, on        the side of a recess made in the articulating surface of a joint        and a positioning mark on a guide tool to be used for        facilitating placement of said implant in a recess of the joint.

In certain embodiments, the technology disclosed relates to a method fordesigning an implant, comprising:

-   -   designing a contour curvature of the implant so that an        articulating surface of the implant is designed to correspond to        a simulated healthy articulating surface of a damaged        articulating surface of a joint, said designing of the implant        comprising placing, in a virtual 3D view, at least two        substantially circular shapes such that each of said circular        shapes is partly overlapping at least one other circular shape;        and    -   providing at least one positioning mark on at least one of said        at least two substantially circular shapes such that said at        least one positioning mark is designed to be used for        determining the orientation in which the implant is to be placed        in a recess made in a damaged articulating surface of a joint.

In embodiments, the technology disclosed relates to a method fordesigning an implant, comprising:

-   -   designing a contour curvature of the implant so that an        articulating surface of the implant is designed to correspond to        a simulated healthy articulating surface of a damaged        articulating surface of a joint, said designing of the implant        comprising placing, in a virtual 3D view, at least two        substantially circular shapes such that each of said circular        shapes is partly overlapping at least one other circular shape        in that the combined area of the circular shapes is designed to        cover, or partly cover, a damaged area; and    -   providing at least one positioning mark on at least one of said        at least two substantially circular shapes such that said at        least one positioning mark is designed to be used for        determining the orientation in which the implant is to be placed        in a recess made in a damaged articulating surface of a joint.

In embodiments, the technology disclosed relates to a design methodcomprising the (further) steps of:

-   -   designing the shape and size of the implant dependent on the        size and shape of the damage in the articulating surface and        dependent on the curvature of the simulated healthy contour of        the articulating surface in the area substantially coinciding        with the damage; and    -   designing the positioning mark to point out the same direction,        or joint axis, as at least one of a mark to be made on the side        of a recess made in the articulating surface of the joint and a        positioning mark on a guide tool to be used for facilitating        placement of said implant.

In embodiments, the present invention relates to a design method fordesigning a guide tool 12 comprising a guide channel 54 for use duringcartilage repair in a joint where the design method comprises theplacement of a positioning mark 500 on the guide tool, wherein thepositioning mark 500 is designed to be aligned with the center 503 ofsaid guide channel in a determined joint axis 501 direction and therebyindicating a placement direction of the guide tool 12 in relation to theselected joint axis 501 during use of the guide tool 12

In another embodiment the present invention relates to a design methodfor designing a guide tool 12 which is intended for use during cartilagerepair in a joint wherein the design method comprises a step forplacement of a positioning mark on the guide tool which indicates aplacement direction of the guide tool in relation to the joint.

In another embodiment, the present invention relates to a design methodfor designing a guide tool 12 which is intended for use during cartilagerepair in a joint wherein the design method comprises;

-   -   a step for placement or design of a positioning mark on the        guide tool wherein the position mark indicates a placement        direction of the guide tool in relation to the joint wherein the        placement direction is used during placement of the guide tool        12 in the joint.

In different embodiments, the present invention further relates to thedifferent alternatives described below in any combination.

In embodiments, the technology disclosed relates to a design method fordesigning a guide tool 12 wherein the step for placement of thepositioning mark of the guide tool in comparison to the joint where theguide tool is to be placed an in relation to a guide channel comprisedin the positioning body 11 of the guide tool 12, and wherein theposition mark placed on a top surface 52 indicate to the surgeon of howto place the guide tool on the joint during cartilage repair by that theplacement of the positioning mark indicates a placement direction of theguide tool in relation to the joint.

In embodiments, the technology disclosed relates to a design method fordesigning a guide tool 12 wherein the placement of said positioning markis on a top surface 52 or top of the guide channel or a surface which isvisible for the surgeon during usage.

In embodiments, the technology disclosed relates to a method ofdesigning a guide tool 12 according to the invention further comprisingthe steps of:

-   -   generating information of a cartilage damage    -   using information about said cartilage damage to determine size        and shape of implant and/or size and shape of cartilage and/or        bone needed to be removed in order to repair said damage    -   using information about said cartilage damage to determine size        and shape of a cartilage size and spread of a contact surface 52        of the guide tool 12 designed to follow the shape and curvature        of the individual cartilage in said joint    -   designing a guide tool 12 based on information of cartilage        damage and the determined size and shape of implant and/or size        and shape of cartilage and/or bone needed to be removed in order        to repair said damage.

In embodiments, the technology disclosed relates to a method ofdesigning a guide tool 12 wherein the direction pointed out by theposition mark in relation to the joint where the guide is a directionsuch as; anterior or posterior, right lateral or left lateral, dorsal orventral, proximal or distal in relation to the placement of the guidetool 12 in a joint.

In embodiments, the technology disclosed relates to a method ofdesigning insert tools designed to comprise positioning marks which isdesigned to be aligned with the positioning mark of the guide tool 12when the insert tools are placed in the guide tool in start position,indicating the correct rotational start position of the insert tools tothe surgeon during use of the guide tool and insert tools duringsurgery.

In embodiments, the technology disclosed relate to guide tool or inserttools or an implant designed according to any of the precedingembodiments.

In embodiments, the design method of the technology disclosed maycomprises the basic blocks of:

I. Determining physical parameters for a cartilage damage in a joint andthen using this information in order to;

II. Generate design parameters of a medical implant 10.

III. Generate design parameters of a guide tool 12 for use duringimplantation of said implant.

In embodiments, the physical parameters as well as the design parametersare represented as digital data that is processed or generated byspecifically designed computer program code portions executed in a dataprocessing system. The system may be fully automated or may compriseportions of computer supported manual steps of for example selections.The design parameters resulting from the process may be stored in aformat suitable for use as input in an automated manufacturing process.

In embodiments, the design method includes the further step of:

IV. Determine a positioning mark placement which placement helps thesurgeon to determine the orientation of the placement of the guide toolin a joint, wherein the positioning mark for example may be chosen to beplaced in a position on the guide tool which indicate an orientationselected from a position or direction on the patient which is known forthe surgeon and based on the anatomy of a patient selected, for exampleselected from anterior or posterior, right lateral or left lateral,dorsal or ventral, proximal or distal orientation or axis direction, andwherein blocks II-IV of the described design method above can beperformed in any desired order.

The technology disclosed relates to a method for designing an implantcomprising the steps of designing a contour curvature of the implant sothat an articulating surface of the implant is designed to correspond toa simulated healthy articulating surface of a damaged articulatingsurface of a joint, where the designing of the implant comprises thestep of placing, in a virtual 3D view, at least two substantiallycircular shapes such that each of said circular shapes is partlyoverlapping at least one other circular shape in that the combined areaof the circular shapes is designed to cover, or partly cover, an damagedarea, and the step of providing at least one positioning mark on atleast one of said at least two substantially circular shapes such thatsaid at least one positioning mark is designed to be used fordetermining the orientation in which the implant is to be placed in arecess made in a damaged articulating surface of a joint.

In embodiments, the technology disclosed relates to a method fordesigning an implant comprising the steps of:

-   -   designing a contour curvature of the implant so that an        articulating surface of the implant is designed to correspond to        a simulated healthy articulating surface of a damaged        articulating surface of a joint, said designing of the implant        comprising placing, in a virtual 3D view, at least two        substantially circular shapes such that each of said circular        shapes is partly overlapping at least one other circular shape        in that the combined area of the circular shapes is designed to        cover, or partly cover, a damaged area;    -   providing at least one positioning mark on at least one of said        at least two substantially circular shapes such that said at        least one positioning mark is designed to be used for        determining the orientation in which the implant is to be placed        in a recess made in a damaged articulating surface of a joint;        and    -   providing the at least one positioning mark on only one of said        at least two substantially circular shapes of the implant so        that said at least one positioning mark is designed to be        pointing in an anatomic dependent direction, thereby providing        for a correct orientation of the implant when inserted in a        recess made in a damaged articulating surface of a joint.

In embodiments, the technology disclosed relates to a method fordesigning an implant comprising the steps of:

-   -   designing a contour curvature of the implant so that an        articulating surface of the implant is designed to correspond to        a simulated healthy articulating surface of a damaged        articulating surface of a joint, said designing of the implant        comprising placing, in a virtual 3D view, at least two        substantially circular shapes such that each of said circular        shapes is partly overlapping at least one other circular shape        in that the combined area of the circular shapes is designed to        cover a damaged area on the articulating surface of a joint;    -   providing at least one positioning mark on at least one of said        at least two substantially circular shapes such that said at        least one positioning mark is designed to be used for        determining the orientation in which the implant is to be placed        in a recess made in a damaged articulating surface of a joint;        and    -   designing the at least one positioning mark on at least one of        said at least two substantially circular shapes of the implant        so that the direction of the positioning of the mark on the        contour curvature of the implant, corresponding to a simulated        healthy articulating surface reconstructed from a 3D model based        on one or more images taken with MRI or CT-scanning of a damaged        articulating surface of a joint, is determining the orientation        in which the implant is to be placed in the recess.

In embodiments, the technology disclosed relates to a method fordesigning an implant comprising the steps of:

-   -   designing a contour curvature of the implant so that an        articulating surface of the implant is designed to correspond to        a simulated healthy articulating surface of a damaged        articulating surface of a joint, said designing of the implant        comprising placing, in a virtual 3D view, at least two        substantially circular shapes such that each of said circular        shapes is partly overlapping at least one other circular shape        in that the combined area of the circular shapes is designed to        cover, or partly cover, an damaged area on the articulating        surface;    -   providing at least one positioning mark on at least one of said        at least two substantially circular shapes such that said at        least one positioning mark is designed to be used for        determining the orientation in which the implant is to be placed        in a recess made in a damaged articulating surface of a joint;        and    -   designing the at least one positioning mark of the implant so        that the direction of the positioning mark on the contour        curvature of the implant is determining the placement        orientation of the implant in a recess in that said placement        orientation of said at least one positioning mark is also to be        indicated by a mark made on the side of a recess made in the        articulating surface of a joint.

In embodiments, the technology disclosed relates to a method fordesigning an implant comprising the steps of:

-   -   designing a contour curvature of the implant so that an        articulating surface of the implant is designed to correspond to        a simulated healthy articulating surface of a damaged        articulating surface of a joint, said designing of the implant        comprising placing, in a virtual 3D view, at least two        substantially circular shapes such that each of said circular        shapes is partly overlapping at least one other circular shape        in that the combined area of the circular shapes is designed to        cover, or partly cover, an articulate damage;    -   providing at least one positioning mark on at least one of said        at least two substantially circular shapes such that said at        least one positioning mark is designed to be used for        determining the orientation in which the implant is to be placed        in a recess made in a damaged articulating surface of a joint;    -   designing the shape and size of the implant dependent on the        size and shape of the articulate damage and further dependent on        the curvature of the contour of the articulating surface in the        area substantially coinciding with the articulate damage; and    -   designing the positioning mark to point out a direction in        relation to an anatomic dependent direction.

In embodiments, the technology disclosed describes a design method fordesigning an implant, comprising:

-   -   placing, in a virtual 3D view, at least two substantially        circular shapes such that each of the circular shapes is partly        overlapping at least one other circular shape in that the        combined area of the circular shapes is designed to cover, or        partly cover, an articulate damage, and    -   providing at least one positioning mark on at least one of the        at least two substantially circular shapes such that the at        least one positioning mark is designed to be used for        determining the orientation in which the implant is to be placed        in a recess made in a damaged articulating surface of a joint.

In embodiments, the above-mentioned design methods for designing animplant may further comprise designing a contour curvature of theimplant so that an articulating surface 15 of the implant is designed tocorrespond to a simulated healthy articulating surface of a damagedarticulating surface of a joint.

In embodiments, the above-mentioned design methods for designing animplant may further comprise designing the at least one positioning markof the implant so that the direction of the positioning mark on thecontour curvature of the implant is determining the placementorientation of the implant in a recess in that the placement orientationof the at least one positioning mark is also to be indicated by a markmade on the side of a recess made in the articulating surface of ajoint.

In embodiments, the above-mentioned design methods for designing animplant may also comprise providing the at least one positioning mark ononly one of the at least two substantially circular shapes of theimplant so that the at least one positioning mark is designed to bepointing in an anatomic dependent direction, thereby providing for acorrect orientation of the implant when inserted in a recess made in adamaged articulating surface of a joint.

In embodiments, the technology disclosed further comprise an implantdesigned using the above design method for designing an implant,including placing, in a virtual 3D view, at least two substantiallycircular shapes, and providing at least one positioning mark on at leastone of the at least two substantially circular shapes such that the atleast one positioning mark is designed to be used for determining theorientation in which the implant is to be placed in a recess made in adamaged articulating surface of a joint.

In embodiments, the technology disclosed describes a medical implantcomprising at least one positioning mark is parted from the center ofthe articulating surface of at least one of said at least twosubstantially circular shapes of the implant, thereby being adapted tobe used for positioning the medical implant in a recess.

In embodiments, the technology disclosed describes a medical implantcomprising at least two substantially circular shapes such that each ofthe circular shapes is partly overlapping at least one other circularshape, and wherein at least one of the at least substantially circularshapes is provided with at least one positioning mark on its surface sothat the at least one positioning mark is parted from the center,thereby being adapted to be used for (rotationally) positioning themedical implant.

In embodiments, at least one positioning mark is provided on thearticulating surface 15, i.e. the top surface 15 facing the articulatingpart of the joint, of at least one of the at least two substantiallycircular shapes of the medical implant.

In certain embodiments, only one of the at least two substantiallycircular shapes is provided with a positioning mark on its articulatingsurface 15, i.e. the top surface 15 facing the articulating part of thejoint, and the other circular shape(s) is not provided with apositioning mark. The surgeon, or vision system associated with a robotor used in computer-assisted surgery, may then easily detect which ofthe at least two circular shapes is provided with a positioning mark andthen rotationally positioning the medical implant by directing thepositioning mark on the articulating surface 15 of one of the circularshapes towards a feature or mark made on e.g. the cartilage surface of apatient or a storage unit for the implant.

In embodiments, at least one positioning mark is provided on thecartilage contacting surface 19, i.e. the side edge surface 19, of atleast one of the at least two substantially circular shapes.

In certain embodiments, only one of the at least two circular shapes isprovided with a positioning mark on its the cartilage contacting surface19, i.e. side edge surface, and the other circular shape(s) is notprovided with a positioning mark. The surgeon, or vision systemassociated with a robot or used in computer-assisted surgery, may theneasily detect which of the at least two circular shapes is provided witha positioning mark and then rotationally positioning the medical implantby directing the positioning mark on the cartilage contacting surface 19of one of the circular shapes towards a feature or mark made on e.g. thecartilage surface of a patient or a storage unit for the implant.

The technology disclosed describes a medical implant comprising at leasttwo substantially circular shapes such that each of the circular shapesis partly overlapping at least one other circular shape, and wherein atleast one of the at least substantially circular shapes is provided withat least one positioning mark on its surface.

In embodiments, the at least one positioning mark is parted from thecenter of the articulating surface of at least one of the at least twosubstantially circular shapes of the implant, thereby being adapted tobe used for (rotationally) positioning the medical implant.

In embodiments, only one of the at least two circular shapes is providedwith a positioning mark and the other circular shape(s) is not providedwith a positioning mark, thereby facilitating the identification of thepositioning mark when (rotationally) positioning the implant.

In embodiments, the positioning mark is provided on the articulatingsurface of at least one of the at least two substantially circularshapes.

In embodiments, only one of the at least two circular shapes is providedwith at least one positioning mark on its articulating surface and theother circular shape(s) is not provided with a positioning mark on itsarticulating surface, thereby facilitating the identification of thepositioning mark when positioning the implant.

In embodiments, the positioning mark is provided on the cartilagecontacting surface of at least one of the at least two substantiallycircular shapes.

In embodiments, only one of the at least two circular shapes is providedwith at least one positioning mark on its cartilage contacting surfaceand the other circular shape(s) is not provided with a positioning mark,thereby facilitating the identification of the positioning mark whenpositioning the implant.

In embodiments, the technology disclosed describes a method forinserting an implant in a joint, comprising:

-   -   providing an implant having at least one positioning mark,        wherein the at least one positioning mark is positionally        adapted on the surface of the implant to be visible for        detection by a vision system, and    -   detecting, by the vision system, the at least one positioning        mark in relation to at least one of at least one mark made on        the side of a recess made in the articulating surface of the        joint and at least one pre-determined anatomic dependent        direction.

In embodiments, the method for inserting an implant in a joint mayfurther comprise inserting the implant in the recess by directing the atleast one implant positioning mark in a direction dependent on thedirection of at least one of at least one mark made on the side of arecess made in the articulating surface of the joint and at least onepre-determined anatomic dependent direction, wherein the step ofinserting is aided by the step of detecting by the vision system in theabove method for inserting an implant in a joint.

In embodiments, the method for inserting an implant in a joint mayfurther comprise detecting an implant positioning mark on thearticulating surface 15, i.e. of one substantially circular shape amongat least two partly overlapping substantially circular shapes of theimplant and/or detecting an implant positioning mark on the cartilagecontacting surface 19, i.e. the side edge surface 19, of the implant.

The technology disclosed relates to a method for inserting an implant ina joint, comprising:

-   -   providing an implant having at least one positioning mark,        wherein said at least one positioning mark is positionally        adapted on the surface of the implant to be visible for        detection by a vision system;    -   detecting, by the vision system, said at least one positioning        mark in relation to at least one of at least one mark made on        the side of a recess made in the articulating surface of the        joint and at least one pre-determined anatomic dependent        direction; and    -   inserting the implant in the recess by directing the at least        one implant positioning mark in a direction dependent on the        direction of at least one of at least one mark made on the side        of a recess made in the articulating surface of the joint and at        least one pre-determined anatomic dependent direction, wherein        said inserting is aided by said detecting by the vision system.

In embodiments, the technology disclosed relates to a method forinserting an implant in a joint, comprising:

-   -   providing an implant having at least one positioning mark,        wherein said at least one positioning mark is positionally        adapted on the surface of the implant to be visible for        detection by a vision system;    -   detecting, by the vision system, said at least one positioning        mark in relation to at least one of at least one mark made on        the side of a recess made in the articulating surface of the        joint and at least one pre-determined anatomic dependent        direction; and    -   inserting the implant in the recess by directing the at least        one implant positioning mark in a direction dependent on the        direction of at least one of at least one mark made on the side        of a recess made in the articulating surface of the joint and at        least one pre-determined anatomic dependent direction, wherein        said inserting is aided by said detecting by the vision system,        and wherein said detecting by said vision system comprises        detecting an implant positioning mark on the cartilage        contacting surface of the implant.

In embodiments, the technology disclosed relates to a method forinserting an implant in a joint, comprising:

-   -   providing an implant having at least one positioning mark,        wherein said at least one positioning mark is positionally        adapted on the surface of the implant to be visible for        detection by a vision system;    -   detecting, by the vision system, said at least one positioning        mark in relation to at least one of at least one mark made on        the side of a recess made in the articulating surface of the        joint and at least one pre-determined anatomic dependent        direction; and    -   inserting the implant in the recess by directing the at least        one implant positioning mark in a direction dependent on the        direction of at least one of at least one mark made on the side        of a recess made in the articulating surface of the joint and at        least one pre-determined anatomic dependent direction, wherein        said inserting is aided by said detecting by the vision system,        wherein said inserting of the implant in the recess is performed        by use of at least one mechanical arm, e.g. a robot arm, such        that the software-controlled movement of said at least one        mechanical arm is aided by said detecting of said at least one        implant positioning mark in relation to at least one of at least        one mark made on side of the recess and at least one        pre-determined anatomic dependent direction.

In embodiments, the technology disclosed relates to a method forinserting an implant in a joint, comprising:

-   -   providing an implant having at least one positioning mark,        wherein said at least one positioning mark is positionally        adapted on the surface of the implant to be visible for        detection by a vision system;    -   detecting, by the vision system, said at least one positioning        mark in relation to at least one of at least one mark made on        the side of a recess made in the articulating surface of the        joint and at least one pre-determined anatomic dependent        direction; and    -   inserting the implant in the recess by directing the at least        one implant positioning mark in a direction dependent on the        direction of at least one of at least one mark made on the side        of a recess made in the articulating surface of the joint and at        least one pre-determined anatomic dependent direction, wherein        said inserting is aided by said detecting by the vision system,        wherein said inserting of the implant in the recess is performed        by use of at least one mechanical arm, e.g. a robot arm, such        that said step of inserting by said at least one mechanical arm        is aided by said detecting in that at least one sensor and/or        camera is producing at least one of sensor data, at least one        still image and video images indicating the relative positioning        of at least one of said at least one implant positioning mark in        relation to at least one of at least one mark made on side of        the recess and at least one pre-determined anatomic dependent        direction.

In embodiments, the technology disclosed relates to a method forinserting an implant in a joint, comprising:

-   -   providing an implant having at least one positioning mark,        wherein said at least one positioning mark is positionally        adapted on the surface of the implant to be visible for        detection by a vision system;    -   detecting, by the vision system, said at least one positioning        mark in relation to at least one of at least one mark made on        the side of a recess made in the articulating surface of the        joint and at least one pre-determined anatomic dependent        direction; and        inserting the implant in the recess by directing the at least        one implant positioning mark in a direction dependent on the        direction of at least one of at least one mark made on the side        of a recess made in the articulating surface of the joint and at        least one pre-determined anatomic dependent direction, wherein        said inserting is aided by said detecting by the vision system,        wherein the contour curvature of said implant corresponds to a        simulated healthy articulating surface reconstructed from a 3D        model based on one or more images of the joint where the implant        is to be inserted.

In embodiments, the method for inserting an implant in a joint mayfurther comprise inserting the implant in the recess by use of at leastone mechanical arm, e.g. a robot arm, such that the software-controlledmovement of the at least one mechanical arm is aided by the detecting ofthe at least one implant positioning mark in relation to at least one ofat least one mark made on side of the recess and at least onepre-determined anatomic dependent direction.

In embodiments, the technology disclosed describes a method forinserting an implant in a joint using a storage unit, comprising:

-   -   providing an implant having at least one positioning mark,        wherein the at least one positioning mark is located on the        surface of the implant to be visible for detection, and        providing a storage unit, e.g. a box, for storing an implant        prior to inserting the implant in a recess of a human joint.

In embodiments, the method for inserting an implant in a joint using astorage unit may further comprise a storage unit comprising at least oneof a mechanical recess structure and/or holding means adapted forpositioning the implant in a rotationally fixed position in the storageunit, where the storage unit further comprises at least one referencefeature such as a positioning mark, an edge and/or a corner.

In embodiments, the method for inserting an implant in a joint using astorage unit may further comprise detecting the at least one positioningmark in relation to the at least one reference feature and placing theimplant in the storage unit by directing the at least one implantpositioning mark on the surface of the implant in a specific, e.g.pre-determined, rotational direction in relation to the at least onereference feature of the storage unit.

In embodiments, the method for inserting an implant in a joint using astorage unit may further comprise the actions of gripping the implant inthe storage unit, where the implant is rotationally oriented inaccordance with the specific rotational direction of the at least oneimplant positioning mark in relation to the at least one referencefeature of the storage unit, and removing the implant from the storageunit, where the implant is rotationally oriented in accordance with thespecific rotational direction of the at least one implant positioningmark in relation to the at least one reference feature of the storageunit when removed from the storage; unit.

In embodiments, the method for inserting an implant in a joint using astorage unit may further comprise the action of inserting the implant ina recess made in a human joint in a correct placement orientation, wherethe correct placement orientation is determined by how the implant isrotationally positioned in the storage unit in relation to the at leastone reference feature of the storage unit.

In embodiments, the technology disclosed describes a storage unit forstoring, or holding, an implant prior to inserting the implant in arecess made in a joint, where the storage unit comprises at least one ofa mechanical recess structure and/or holding means adapted forpositioning the implant in a rotationally fixed position in the storageunit, and where the storage unit further comprises at least onereference feature such as a positioning mark, an edge and/or a corner.

In embodiments, the reference feature of the above storage unit isadapted to be used for rotationally positioning the implant in thestorage unit in that at least one positioning mark of the implant may beused for rotationally positioning the implant in relation to the atleast one reference feature. The implant may then be placed in thestorage unit by directing the at least one implant positioning mark onthe surface of the implant in a specific, e.g. pre-determined,rotational direction in relation to the at least one reference featureof the storage unit.

In embodiments, the technology disclosed describes a method forinserting an implant in a joint, comprising:

-   -   providing an implant having at least one positioning mark,        wherein said at least one positioning mark is located on the        surface of the implant to be visible for detection;    -   providing a storage unit, e.g. a box, for storing an implant        prior to inserting the implant in a recess of a human joint,        wherein said storage unit comprises at least one of a mechanical        recess structure and/or holding means adapted for positioning        the implant in a rotationally fixed position in the storage        unit, and wherein said storage unit further comprises at least        one reference feature;    -   detecting said at least one positioning mark in relation to said        at least one reference feature;    -   placing the implant in the storage unit by directing the at        least one implant positioning mark on the surface of the implant        in a specific, e.g. pre-determined, rotational direction in        relation to said at least one reference feature of the storage        unit;    -   gripping the implant in the storage unit, wherein the implant is        rotationally oriented in accordance with said specific        rotational direction of the at least one implant positioning        mark in relation to said at least one reference feature of the        storage unit;    -   removing the implant from the storage unit, wherein the implant        is rotationally oriented in accordance with said specific        rotational direction of the at least one implant positioning        mark in relation to said at least one reference feature of the        storage unit when removed from the storage unit; and    -   inserting the implant in a recess made in a human joint in a        correct placement orientation, wherein said correct placement        orientation is determined by how the implant is rotationally        positioned in said storage unit in relation to said at least one        reference feature of the storage unit.

In embodiments, the technology disclosed describes a method forinserting an implant in a joint, comprising:

-   -   providing an implant having at least one positioning mark,        wherein said at least one positioning mark is located on the        surface of the implant to be visible for detection;    -   providing a storage unit, e.g. a box, for storing an implant        prior to inserting the implant in a recess of a human joint,        wherein said storage unit comprises at least one of a mechanical        recess structure and/or holding means adapted for positioning        the implant in a rotationally fixed position in the storage        unit, and wherein said storage unit further comprises at least        one reference feature;    -   detecting said at least one positioning mark in relation to said        at least one reference feature;    -   placing the implant in the storage unit by directing the at        least one implant positioning mark on the surface of the implant        in a specific, e.g. pre-determined, rotational direction in        relation to said at least one reference feature of the storage        unit;    -   gripping the implant in the storage unit, wherein the implant is        rotationally oriented in accordance with said specific        rotational direction of the at least one implant positioning        mark in relation to said at least one reference feature of the        storage unit;    -   removing the implant from the storage unit, wherein the implant        is rotationally oriented in accordance with said specific        rotational direction of the at least one implant positioning        mark in relation to said at least one reference feature of the        storage unit when removed from the storage unit; and    -   inserting the implant in a recess made in a human joint in a        correct placement orientation, wherein said correct placement        orientation is determined by how the implant is rotationally        positioned in said storage unit in relation to said at least one        reference feature of the storage unit, wherein said step of        detecting said at least one positioning mark in relation to said        at least one reference feature when placing the implant in the        storage unit is performed by a vision and/or sensor system        comprising at least one camera and/or sensor, the vision and/or        sensor system is thereby aiding the correct placement of the        implant in the storage unit.

In embodiments, the technology disclosed describes a method forinserting an implant in a joint, comprising:

-   -   providing an implant having at least one positioning mark,        wherein said at least one positioning mark is located on the        surface of the implant to be visible for detection;    -   providing a storage unit, e.g. a box, for storing an implant        prior to inserting the implant in a recess of a human joint,        wherein said storage unit comprises at least one of a mechanical        recess structure and/or holding means adapted for positioning        the implant in a rotationally fixed position in the storage        unit, and wherein said storage unit further comprises at least        one reference feature;    -   detecting said at least one positioning mark in relation to said        at least one reference feature;    -   placing the implant in the storage unit by directing the at        least one implant positioning mark on the surface of the implant        in a specific, e.g. pre-determined, rotational direction in        relation to said at least one reference feature of the storage        unit;    -   gripping the implant in the storage unit, wherein the implant is        rotationally oriented in accordance with said specific        rotational direction of the at least one implant positioning        mark in relation to said at least one reference feature of the        storage unit;    -   removing the implant from the storage unit, wherein the implant        is rotationally oriented in accordance with said specific        rotational direction of the at least one implant positioning        mark in relation to said at least one reference feature of the        storage unit when removed from the storage unit; and    -   inserting the implant in a recess made in a human joint in a        correct placement orientation, wherein said correct placement        orientation is determined by how the implant is rotationally        positioned in said storage unit in relation to said at least one        reference feature of the storage unit, wherein said steps of        gripping the implant in the storage unit, removing the implant        from the storage unit and inserting the implant in the human        joint in a correct placement orientation are performed by the        use of at least one mechanical arm, e.g. a robot arm, and        wherein said step of inserting said implant in the correct        placement orientation in the recess of the joint is determined        by how the implant is rotationally positioned/oriented in said        storage unit in that the software-controlled movement of the        mechanical arm from the storage unit to the recess is        pre-programmed based on the rotational positioning/orientation        of the implant in the storage unit.

BRIEF DESCRIPTION OF THE FIGURES

The invention will be further explained with reference to theaccompanying drawings which are exemplified embodiments according to theinvention and not limiting the scope of the invention:

FIG. 1 schematically illustrates parts of the design process accordingto an embodiment of the inventive concept for designing a surgical kit.

FIG. 2. Shows a medical implant comprising a positioning mark placedusing a guide tool according to the invention and wherein thepositioning mark is placed in an anterior position in relation to a kneejoint.

FIG. 3a-3b . Shows a medical implant according to the invention

FIG. 4a shows a guide tool comprising a positioning mark placed on topof the guide channel in anterior direction (compared to the relation ofplacement of the guide tool in the joint and in relation to the guidechannel).

FIG. 4b shows an insert tool, in this example a reamer guide placedinside the guide channel of the guide tool in a start position and wherethe positioning mark of the guide channel and the positioning mark ofthe insert tool are aligned.

FIG. 5 shows a guide tool according to the invention placed on thecartilage in a joint and further comprising a height adjustment inserttool

FIG. 6 shows a guide tool according to the invention placed on thecartilage in a joint and further comprising a height adjustment inserttool placed in start position inside the guide channel, and wherein thepositioning mark of the guide tool and the positioning mark of theheight adjustment insert tool are aligned and wherein it is shown thatthe center of the guide channel is aligned with the positioning markings500 in an anterior direction of a knee joint.

FIG. 7 shows a guide tool according to the invention placed on thecartilage in a joint and further comprising an implant dummy insert tool36 placed in start position inside the guide channel 54, and wherein thepositioning mark 500 of the guide tool 12 and the positioning mark 500of the implant dummy 36 are aligned and the positioning mark on theimplant dummy is placed on top of the implant dummy shaft.

FIG. 8 shows another view of a guide tool according to the inventionplaced on the cartilage in a joint and further comprising an implantdummy insert tool placed in start position inside the guide channel, andwherein the positioning mark of the guide tool and the positioning markof the implant dummy tool are aligned and the positioning mark on theimplant dummy is placed on top of the implant dummy shaft.

FIG. 9 shows a guide tool according to the invention placed on thecartilage in a joint and further showing a view how it looks like whenthe height adjustment tool 504 has been used inside the guide channeltogether with a reamer and/or drill to make a recess in a desired sizeand depth wherein the implant according to the invention can be placed.

FIG. 10 shows a guide tool according to the invention placed on thecartilage in a joint and further showing how the positioning mark of theguide tool is used to make a mark on side of the recess wherein theimplant is to be placed in order to know in which direction the implantis to be placed in the recess when the guide is removed before placingthe implant in the joint.

FIG. 11 shows a medical implant comprising a positioning mark accordingto the invention and wherein the direction of the positioning mark ofthe implant also is indicated on the cartilage surface due to previousguidance using the guide tool according to the invention during surgery.

FIG. 12 shows an exemplified embodiment of a guide tool and insert toolsand implant designed using the design method according to the presentinvention.

FIG. 13a-b shows exemplified embodiments of the guide tool according tothe invention.

FIGS. 14a-b show a medical implant according to the invention whichcomprises two substantially circular shapes where one of the circularshapes is provided with a positioning mark on its articulating surface.

FIGS. 15a-b show a medical implant according to the invention whichcomprises two substantially circular shapes, e.g. designed from using avirtual model comprising two substantially circular shapes, where one ofthe circular shapes is provided with a positioning mark on its cartilagecontacting surface 19, i.e. side edge surface 19.

FIG. 16 shows a storage unit adapted for storing a medical implant ofsubstantially circular shape prior to inserting the medical implant in arecess made in a joint.

FIG. 17 shows a storage unit adapted for storing a medical implantcomprising two circular shapes prior to inserting the medical implant ina recess made in a joint.

DETAILED DESCRIPTION OF THE INVENTION Design Method

The present invention is directed to a system, comprising a method,apparatus and computer programs, for designing a guide tool 12comprising a positioning mark 500, and/or medical implant comprising apositioning mark 500, and/or associated tools comprising positioningmarks and wherein said guide tool 12 insert tool 502 and implant 10 allcomprises a positioning mark 500 marking out the same direction or axisin relation to the joint during use when replacing damaged cartilage ina joint. The associated set of tools is devised for the placement of animplant that replaces damaged cartilage in a joint and is adapted to thespecific implant as well as a specific joint for which the implant isintended. The surgical kit provided by the present invention has theeffect that successful implant insertion is less dependent on surgicalcircumstances and the skills of the surgeon compared to previously knownimplants. Due to the design and the function of using the positioningmarking in guide tool and/or implant and/or inert tools gives improvedimplantation precision and a precise desired placement of the implant inthe joint every time. The precision of the surgery is “built in” intothe design of the tools.

FIG. 1 shows an example of a surgical kit designed according to a methodof one embodiment of the present invention. This particular exemplifyingembodiment of a surgical kit according to the invention is especiallyadapted for cartilage replacement at the femur of a knee joint. Theinvention may however be applied for cartilage replacement in anarticulating surface in any other joint in the body, e.g. elbow, ankle,finger, hip, toe and shoulder. The guide tool 12 according to theinvention may be equipped with a guide-channel 13 and a positioning body11 and may be used together with an implant 10, and a drill guide 8, acutting tool 6, which in this exemplifying embodiment is a punch, adrill-bit 8, preferably equipped with a depth gauge 1 and/or areamer-bit 4, preferably equipped with a depth gauge 3, and/or a hammertool 35 and/or a reamer guide 28, and/or implant dummy 36. The detailsof examples of insert tools 502 which may be used inside the guide tool12 are further described and exemplified below.

FIG. 1 schematically illustrates the design process according to anembodiment of the inventive concept for designing a guide tool and/orinsert tools 502 and/or implant 10.

The design system comprises the basic blocks of:

I. Determining physical parameters for a cartilage damage in a joint andthen using this information in order to;

II. Generate design parameters of a medical implant 10.

III. Generate design parameters of a guide tool 12 for use duringimplantation of said implant.

The physical parameters as well as the design parameters are representedas digital data that is processed or generated by specifically designedcomputer program code portions executed in a data processing system. Thesystem may be fully automated or may comprise portions of computersupported manual steps of for example selections. The design parametersresulting from the process are stored in a format suitable for use asinput in an automated manufacturing process.

IV. Determine a positioning mark placement which placement helps thesurgeon to determine the orientation of the placement of the guide toolin a joint and wherein the positioning mark 500 for example may bechosen to be placed in a position on the guide tool which indicate anorientation selected from a position or direction on the patient whichis known for the surgeon and based on the anatomy of a patient selected,for example selected from anterior or posterior, right lateral or leftlateral, dorsal or ventral, proximal or distal orientation or axisdirection.

and wherein blocks II-IV above can be performed in any order.

In one embodiment according to the invention the design system is asystem to design a guide tool 12 to be used to guide inserts toolsand/or an implant or other cartilage repair objects comprises the basicblocks of:

I. Determining physical parameters for a cartilage damage in a joint andthen using this information in order to;

II. Generate design parameters of a medical implant 10.

III. Generate design parameters of a guide tool 12 for use duringimplantation of said implant. The physical parameters as well as thedesign parameters are represented as digital data that is processed orgenerated by specifically designed computer program code portionsexecuted in a data processing system. The system may be fully automatedor may comprise portions of computer supported manual steps of forexample selections. The design parameters resulting from the process arestored in a format suitable for use as input in an automatedmanufacturing process.

IV. Determine placement for placement of a positioning mark 500 on theguide tool wherein the positioning mark 500 is designed to be alignedwith the center 503 of said guide channel 54 in a determined joint axis501 direction and thereby indicating a placement direction of the guidetool 12 in relation to the selected joint axis 501 during use of theguide tool 12. The direction is also indicated by placement of thepositioning mark 500 of the guide tool 12 on a side of the guide channelwhich faces the chosen direction in relation to the joint.

The placement of the positioning mark on a guide tool, may be on top ofthe guide channel 54 or on top of the positioning body 11 on the side ofthe guide channel or at any place visible for the surgeon using theguide tool.

and wherein blocks II-IV above can be performed in any order.

In one embodiment according to the invention, the insert tools 502 andor the implant 10 is also designed to comprise a position mark 500, andthe position of the position mark is designed to be on a surface whichis visible for the surgeon during surgery and use of the insert tools502 and or implant 10. Example of such surfaces are on the top of theinsert tools, on a surface facing the surgeon during use of the inserttools, for example on a surface opposite to the surface facing thecartilage damage. The positioning marking 500 of an implant 10 may forexample be on the articulating surface 15 of the implant, preferably notplaced in the center but parted from the center of the implant or on asurface which is visible for the surgeon, or for example on a topsurface of an insert tool pointing in the opposite direction compared tothe cartilage contact surface 50 of the positioning body 11.

According to certain aspects, the technology disclosed provides a designmethod that allows for producing an implant which is easy to fit to anindividual damage and an individual patient. The design build-up methodcomprises choosing size, at least two circular shapes, implantthickness, implant surface shape, articular surface etc. for eachimplant. This build-up makes the proposed solution and implant uniqueand easy to individualize, but still suitable for large scale industrialmanufacturing. The design process further comprises designing theimplant to have at least one positioning mark on the surface of one ofthe circular shapes, where the positioning mark is adapted to be usedfor pointing out a direction for placement of the implant in a recess.The circular shapes building up the implant makes the implant easy toplace by drilling and/or reaming, thereby providing for a fit of eachimplant in every patient.

According to certain aspects of the technology disclosed, thepositioning or location of the at least one positioning mark on thesurface of the implant may be determined based on one or more of imagestaken of the damaged cartilage surface of a joint. A technical effect ofintroducing at least one positioning mark on the implant is that thecontour curvature of an articulating surface 15 of the implant body,which is built up from the at least two circular shapes, may be toenable or facilitate orientating and positioning of the implant (e.g. bythe surgeon or a robot) so that the implant is aligned to the cartilagesurface surrounding the recess in a correct way. Furthermore, byintroducing at least one positioning mark on the implant, the contourcurvature of an articulating surface 15 of the implant body may be(rotationally) oriented/positioned in a recess to correspond to asimulated healthy cartilage reconstructed from one or more of the imagestaken of the damaged cartilage surface of the joint.

Embodiments herein relate to design methods for design of an implanthaving at least one positioning mark where the design of the implant isbased on a 3D virtual model of an implant. The design method may thencomprises identifying a damage area, presenting a virtual 3D view of theidentified damage area and creating a 3D virtual implant comprisingvirtually placing in the 3D view a shape. The area of the shape thencovers or partly covers the identified damage area, producing an implantbased on the created 3D virtual implant. The shape comprises at leasttwo substantially circular shapes, where the surface of at least one ofthe at least two substantially circular shape is designed to be providedwith at least one positioning mark. Each circular shape may partlyoverlap at least one other circular shape, and the area of the circularshapes may cover or partly cover the identified damage area.

The method for designing the implant by building up the implant from atleast two circular shapes may further comprise placing at least twopoints, each from where an axis will origin from on the bone surface ofthe joint in or nearby the damage area or on a simulated bone surfacewhich is a virtually created surface covering the damage area. Inembodiments, each circular shape may comprise a respective axis, and theoverlap of the circular shapes may depend on the selection of diameterfor the respective circular shape in combination with the selection ofdistance between an axis of one circular shape and another axis ofanother circular shape.

In certain embodiments, the selections of diameter for respectivecircular shape and distance between axes may be combined with theselection of a desired coverage for the implant of the damage area. Insome embodiments, the identifying of a damage area in a patient may beperformed by taking CT, CBCT, MRI images or the like of a joint of apatient and using the images to create a 3D view of the bone and/orcartilage area using for example a software program useful for virtual3D animation. In embodiments, the design step of using CT, CBCT, MRIimages of a joint to create the 3D view may include determining theposition or location on the surface of the implant for at least onepositioning mark. The position for the at least one positioning mark onthe surface may then be determined from the CT, CBCT, MRI images of thejoint of a patient, thereby being designed for providing for a correctrotational positioning/orientation of the implant in a recess made inthe joint.

In certain embodiments, the positioning mark provided on the surface ofat least one of the plurality of circular shapes of the implant isadapted to be used for alignment of the positioning mark of the implantto a certain anatomic dependent direction associated with the joint inwhich the implant is to be inserted. The introduction of a positioningmark on the surface of one circular shape may be particularly beneficialwhen a plurality of placement options for inserting the implant in arecess exist, e.g. when the implant to be inserted is built-up with aplurality of substantially circular shapes having essentially the samediameter.

By using the design method according to different embodiments herein, asurgeon, or a robot, is provided with a precise way to correctly placeand rotationally position an implant in a recess made in the joint.According to embodiments of the design methods and system of thetechnology disclosed, implant shapes may be built individually dependingon cartilage damage and location of damage in the joint. This providesfor a selection from different sizes of circular shapes, orsubstantially circular shapes, which are partly overlapping each otherand which may or may not be individually selected for one patient,allowing for the surgeon to choose an implant which fits the size andshape of the specific bone and or cartilage damage or defect, andfurther gives the surgeon an easy to use design method and tool set formaking the excisions needed.

In a certain embodiment, at least one positioning mark provided on animplant which is designed to be built-up from and comprise onesubstantially circular shape or a plurality of overlapping substantiallycircular shapes may provide guidance to a surgeon, or a robot having avision system. The vision system may then be adapted and configured fordetecting the at least one of the positioning mark on the surface of theimplant in relation to a mark made on side of a recess, where the markmade on side of the recess may be made in a pre-determined anatomicdependent direction or in a direction/position determined from theprocess for designing the implant. The direction/position of thepositioning mark may then be determined from at least one image taken ofthe damaged joint. Following detection by the vision system of the atleast one of the positioning mark on the implant and the mark made onside of the recess, the implant may be correctly inserted/oriented inthe recess by directing the positioning mark, e.g. provided on thesurface of one of the implant's circular shapes, in at least one of thedirection of a mark previously made on side of the recess (whichposition may be determined in the design process) and in apre-determined anatomic dependent direction. Here, by correctlyinserted/oriented, it is meant that the contour curvature of anarticulating surface 15 of the implant, which may be designed based on a3D virtual implant created using one or more CT, CBCT, MRI images or thelike of a joint of a patient, corresponds to a simulated healthycartilage reconstructed from one or more of the images taken of thedamaged cartilage surface of the joint and that the contour curvature ofthe articulating surface 15 of the implant may further be aligned to thecartilage surface surrounding the recess.

In a certain embodiment of a surgical method using the technologydisclosed, no mark is made on side of the recess but the detection ofthe positioning mark on the surface of at least one of the circularshapes, which may be detected by e.g. a vision system associated with arobot or in computer-assisted surgery, is used for pointing thepositioning mark in a pre-determined anatomic dependent direction sothat the implant is correctly placed in the recess. This may provide thesame effect as mentioned above in that the implant, which is designedbased on a 3D virtual implant created using one or more CT, CBCT, MRIimages or the like of a joint of a patient, may be correctlyinserted/oriented in the recess in that the contour curvature for thearticulating surface 15 of the implant corresponds to a simulatedhealthy cartilage reconstructed from one or more of the images taken ofthe damaged cartilage surface of the joint and in that the contourcurvature for the articulating surface 15 of the implant may further bealigned to the cartilage surface surrounding the recess.

In certain embodiments, a guide tool may further be used in the surgicalmethod of inserting an implant in the recess and the positioning markprovided on the implant may then be pointing out a direction forplacement of the implant in a recess in relation to a joint axis withthe guide tool, or an anatomic dependent direction, and may point outthe same direction as a positioning mark on the guide tool used forplacing the implant.

In embodiments, the contour curvature for an articulating surface 15 ofthe implant body of the implant is built-up with at least twosubstantially circular shapes and is dependent on a determined surfacecurvature of the cartilage and/or the subchondral bone. At least one ofthe articulating surface 15 and the cartilage contacting surface 19 ofat least one of the circular shapes is then provided with a positioningmark which is parted from the center of the implant to thereby bedesigned to be pointing out a pre-determined anatomic dependentdirection and/or which is designed to be pointing in the direction of amark made on side of the recess, where the mark made on the recess isindicating the direction in which the implant is to be placed. Thearticulating surface of the implant may then have a curvature thatcorresponds to a simulated healthy cartilage reconstructed from an imagetaken e.g. with MRI or CT-scanning of the damaged cartilage surface ofthe joint.

In certain embodiments, the positioning mark is placed on either thearticulating surface 15 or the cartilage contacting surface 19 of one ofthe plurality of circular shapes of the implant and is adapted to beused for alignment of the positioning mark of the implant, i.e. aligningthe implant, to a mark made on side of the recess, where the mark madeon the recess is indicating the direction in which the positioning markon the surface of one of the plurality of circular shapes is to bedirected to rotationally position the implant correctly in the recess.

According to certain aspects, the technology disclosed describes adesign method for designing of an individually customized implant, wherea second virtual model making step comprises making a 3D model of avirtual implant including a step of virtually placing in the 3D view atleast two circular shapes, where each of the at least two circularshapes is partly overlapping at least one other circular shape.

According to other aspects, the technology disclosed describes a designmethod for design of an individually customized implant provided with apositioning mark and comprising at least two substantially circularshapes, where each circular shape comprises an axis and where an overlapof the circular shapes depends on selection of diameter of thesubstantially circular shapes in combination of selection of closenessof an axis of one circular shape in relation to another axis of anothercircular shape in combination with selection of desired coverage for theimplant of the bone and/or cartilage damage.

In an automated process, a computer program, for example a radiographysoftware program, could be adapted to scan the images for predeterminedcharacteristics of an area and or spread, curvature and or a location ofbone and/or cartilage damage in the image data. The automatically marked2D images may then be combined into a 3D view which may be called thedamage representation CAD animation model. The size of the area which isof interest to map or to create a 3D view of is usually not depending ofthe size of the cartilage damage and the type of joint or bone partwhich is to be repaired, usually the surgeon does not know where in thejoint the damage is located before taking images of the patients joint,therefore typically, images of the whole bone and or cartilage area ofthe joint are used to create a virtual 3D view. A virtual 3D view is ajoint representation CAD animation model which may be selected to showthe bone and or cartilage area, the bone and or cartilage damage,placement of virtual implants etc.

In certain embodiments, a first damage identification step of the designmethod according to embodiments herein comprises identifying a boneand/or cartilage area in a patient by taking images of the injury ordamage in the joint of a patient and then use these images of theindividual patient's bone and/or cartilage area to create a jointrepresentation CAD animation model. In embodiments, the technologydisclosed relates to a method for designing an implant comprisingdesigning the implant so that the contour curvature of an articulatingsurface 15 of the implant is designed to correspond to a simulatedhealthy articulating surface of a damaged articulating surface of ajoint. The method for designing the implant may then comprise placing,in a virtual 3D view, at least two substantially circular shapes suchthat each of the circular shapes is partly overlapping at least oneother circular shape in that the combined area of the circular shapes isdesigned to cover, or partly cover, a damaged area. The method fordesigning the implant by creating a virtual 3D view may further includedetermining a position for an implant positioning mark and/or the actualdesign of the positioning mark in the same design process steps thatinclude placing the at least two substantially circular shapes in thevirtual 3D view.

Hence, the method for designing the implant may further includedesigning the implant by providing at least one positioning mark on atleast one of the at least two substantially circular shapes in thevirtual 3D view such that the at least one positioning mark is designedto be used for determining the rotational orientation in which theimplant is to be placed in a recess made in a damaged articulatingsurface of a joint. In embodiments, the design method may furtherincludes providing the at least one of the at least one positioning markon the articulating surface 15, i.e. the top articulating surface 15, ofone of the at least two substantially circular shapes and/or providingthe at least one positioning mark on the cartilage contacting surface19, i.e. the side edge surface, of one of the at least two substantiallycircular shapes of the implant. The positioning mark on the articulatingsurface 15 is then parted from the center of the implant to be adaptedfor rotationally positioning the implant. In embodiments, thepositioning mark on the articulating surface 15 may preferably be placedon the surface peripheral of the articulating surface 15.

The design method may further include designing the contour curvature ofthe implant so that the articulating surface 15 of the implant and theat least one positioning mark correspond to a simulated healthyarticulating surface reconstructed from a 3D model based on one or moreimages taken with MRI or CT-scanning of a damaged articular surface of ajoint. In certain embodiment, the design method may then includedesigning the implant by providing the at least one positioning mark ononly one of the at least two substantially circular shapes in thevirtual 3D view for the implant so that the at least one positioningmark is designed to be pointing in an anatomic dependent direction or amark to be made on side of a recess in which the implant is to beinserted, thereby providing for a correct rotational orientation of theimplant when inserted in the recess made in a damaged articulatingsurface of the joint.

In other embodiments, the design method may include designing the atleast one positioning mark of the implant so that the direction of thepositioning mark on the contour curvature of the articulating surface 15of one circular shape of the plurality of circular shapes of the implantis determining the rotational placement orientation of the implant in arecess in that the placement direction of the at least one positioningmark is also to be indicated by a mark made on the side of a recess madein the articulating surface of a joint. The positioning mark on thearticulating surface 15 of one circular shape of the plurality ofcircular shapes is then parted from the center of the implant to beadapted for rotationally positioning the implant. In embodiments, thepositioning mark on the articulating surface 15 of one circular shape ofthe plurality of circular shapes may preferably be placed on the surfaceperipheral of the articulating surface 15.

In embodiments, the technology disclosed relates to a method forinserting an implant in a joint comprising providing an implant havingat least one positioning mark, wherein the at least one positioning markis positionally adapted on the surface of the implant to be visible fordetection by a vision system. The method for inserting an implant maythen further include detecting, by the vision system, the at least onepositioning mark in relation to at least one of at least one mark madeon the side of a recess in the articulating surface of the joint and atleast one pre-determined anatomic dependent direction. The insertion ofthe implant in the recess may be performed by directing the at least oneimplant positioning mark in a direction dependent on the direction of atleast one of at least one mark made on the side of a recess made in thearticulating surface of the joint and at least one pre-determinedanatomic dependent direction. The insertion may then be aided by thedetecting by the vision system.

In embodiments, the inserting of the implant in the recess may beperformed by directing the at least one implant positioning mark in thedirection of at least one of at least one mark made on the side of therecess on the articulating surface. In embodiments, the method forinserting an implant in a joint may then include detecting, by a visionsystem, both the mark made on the side of the recess and at least oneimplant positioning mark on the articulating surface 15, i.e. the toparticulating surface 15, of one substantially circular shape among atleast two partly overlapping substantially circular shapes of theimplant. The positioning mark on the articulating surface 15 of onecircular shape of the plurality of circular shapes is then parted fromthe center of the implant to be adapted for rotationally positioning theimplant. In embodiments, the positioning mark on the articulatingsurface 15 of one circular shape of the plurality of circular shapes maypreferably be placed on the surface peripheral of the articulatingsurface 15. In other embodiments, the method for inserting an implant ina joint may include detecting, by a vision system, both the mark made onthe side of the recess and at least one implant positioning mark on thecartilage contacting surface 19, i.e. the side edge surface 19, of theimplant.

Robotic surgery, computer-assisted surgery, and robotically-assistedsurgery are terms for technological developments that use roboticsystems to aid in surgical procedures. Robotically-assisted surgery wasdeveloped to overcome the limitations of pre-existing minimally-invasivesurgical procedures and to enhance the capabilities of surgeonsperforming open surgery.

In the case of robotically-assisted minimally-invasive surgery, insteadof directly moving the instruments, the surgeon may use one of twomethods to control the instruments, either a direct telemanipulator orthrough computer control. A telemanipulator is a remote manipulator thatallows the surgeon to perform the normal movements associated with thesurgery whilst the robotic arms carry out those movements using endeffectors and manipulators to perform the actual surgery on the patient.In computer-controlled systems, the surgeon uses a computer to controlthe robotic arms and its end-effectors, though these systems can alsostill use telemanipulators for their input. One advantage of using thecomputerised method is that the surgeon does not have to be present, butcan be anywhere in the world, leading to the possibility for remotesurgery. In the case of enhanced open surgery, autonomous instrumentsmay replace traditional steel tools, performing certain actions withmuch smoother, feedback-controlled motions than could be achieved by ahuman hand. The main object of such smart instruments is to reduce oreliminate the tissue trauma traditionally associated with open surgerywithout requiring more than a few minutes' training on the part ofsurgeons. This approach seeks to improve open surgeries that have so farnot benefited from minimally-invasive techniques.

In embodiments of the technology disclosed, a computer-assisted surgicalsystem may be used for inserting the implant in a recess. Differenttypes of computer-assisted surgical systems can be used forpre-operative planning, surgical navigation and to assist in performingsurgical procedures.

Robotically-assisted surgical (RAS) devices are one type ofcomputer-assisted surgical system. Sometimes referred to as roboticsurgery, RAS devices enable the surgeon to use computer and softwaretechnology to control and move surgical instruments through one or moretiny incisions in the patient's body (minimally invasive) for a varietyof surgical procedures. The benefits of a RAS device may include itsability to facilitate minimally invasive surgery and assist with complextasks in confined areas of the body. The device is not actually a robotbecause it cannot perform surgery without direct human control.

RAS devices generally have several components, which may include atleast one of the following components:

-   -   1) a console, where the surgeon sits during surgery. The console        is the control center of the device and allows the surgeon to        view the surgical field, e.g. through a 3D endoscope, and        control movement of the surgical instruments;    -   2) a bedside cart that may include at least one mechanical arm,        at least one camera and surgical instruments that the surgeon        may or may not control during surgical procedures; and    -   3) a separate cart that may contain supporting hardware and        software components, such as an electrosurgical unit (ESU),        suction/irrigation pumps, and light source for the camera.

Most surgeons use multiple surgical instruments and accessories with theRAS device, such as scalpels, forceps, graspers, dissectors, cautery,scissors, retractors and suction irrigators.

In these days, there are a lot of medical devices in operation room. Inaddition, several surgical master-slave robots have been commercialized,and are becoming common.

In embodiments of the technology disclosed, a surgical robot comprisingcontrol software may be used for inserting the implant in a recess. Byintroducing surgical robots, it is possible to perform more preciseinsertion of the implant in the recess. In certain embodiments, thesurgeon may uses one of two methods to control the instruments, either adirect telemanipulator or through computer control, and to insert theimplant in the recess.

Typically, the control software has hardware dependencies based onactuators, sensors and various kinds of internal devices.

The method for inserting an implant in a recess according to the presentinvention may include inserting the implant in the recess by use of atleast one mechanical arm, e.g. a robot arm, such that thesoftware-controlled movement of the at least one mechanical arm is aidedby the detecting of at least one implant positioning mark in relation toat least one of at least one mark made on side of the recess and atleast one pre-determined anatomic dependent direction. The method forinserting an implant may then further include detecting, by a visionsystem, the at least one positioning mark in relation to at least one ofat least one mark made on the side of a recess made in the articulatingsurface of the joint and at least one pre-determined anatomic dependentdirection. The insertion of the implant in the recess may be performedby directing the at least one implant positioning mark in a directiondependent on the direction of at least one of at least one mark made onthe side of a recess made in the articulating surface of the joint andat least one pre-determined anatomic dependent direction. The insertionis then aided by the detecting by the vision system.

In embodiments, the inserting of the implant in the recess may beperformed by directing the at least one implant positioning mark in thedirection of at least one of at least one mark made on the side of therecess on the articulating surface. The method for inserting an implantin a joint may then include detecting, by a vision system, an implantpositioning mark on the articulating surface 15, i.e. the top surface15, of one substantially circular shape among at least two partlyoverlapping substantially circular shapes of the implant. In otherembodiments, the method for inserting an implant in a joint may includedetecting, by a vision system, an implant positioning mark on thecartilage contacting surface 19, i.e. the side edge surface 19, of theimplant. The positioning mark on the articulating surface 15 of at leastone circular shape of the plurality of circular shapes is then partedfrom the center of the implant to be adapted for rotationallypositioning the implant. In embodiments, the positioning mark on thearticulating surface 15 of at least one circular shape of the pluralityof circular shapes may preferably be placed on the surface peripheral ofthe articulating surface 15.

In certain embodiments, the inserting of the implant in the recess isperformed by use of at least one mechanical arm, e.g. a robot arm, suchthat the inserting of the implant by the at least one mechanical arm isaided by the detecting by the vision/sensor system in that at least onesensor and/or camera is producing at least one of sensor data, stillimages and video images indicating the relative positioning of at leastone of the at least one implant positioning mark in relation to at leastone of at least one mark made on side of the recess and at least onepre-determined anatomic dependent direction.

In yet another embodiment, the method for inserting an implant furtherincludes providing a guide tool comprising a positioning feature/markand making, by one of a surgeon and a mechanical arm such as a robotarm, a mark on the side of a recess made in an articulating surface ofthe joint in the direction of the positioning mark of the guide tool,thereby determining the future placement orientation of the implant.

In embodiments, the technology disclosed relates to a surgical methodand a storage unit for storing the implant prior to inserting theimplant in a human joint comprising providing an implant having at leastone positioning mark, where the at least one positioning mark may bepositioned or located on the surface of the implant to be visible fordetection. The method for inserting the implant may further involve astorage unit, e.g. a box, for storing an implant prior to inserting theimplant in a recess of a human joint where the storage unit comprises atleast one reference feature such as a positioning mark. The storage unitmay comprise a mechanical recess structure and/or holding means adaptedfor fixing or holding the implant in a rotationally fixed position inthe storage unit and the at least one reference feature of the storage,e.g. a corner/edge of the storage unit or a positioning mark on thesurface of the storage unit, is adapted and/or designed to be used todetermine the rotational orientation of the implant when placed in thestorage unit.

The method for inserting the implant may further include detecting theat least one positioning mark in relation to the at least one referencefeature and placing the implant in the storage unit by directing the atleast one implant positioning mark on the surface of the implant in aspecific, e.g. pre-determined, rotational direction in relation to theat least one reference feature of the storage unit. The method forinserting the implant in a human joint may further include removing theimplant from the storage unit in that the implant is rotationallyoriented in accordance with the specific rotational direction of the atleast one implant positioning mark in relation to the at least onereference feature of the storage unit. This provides the effect that theimplant is removed from the storage unit and inserted in a recess madein a human joint in a correct or more accurate rotational placementorientation. The correct, or more accurate, rotational placementorientation may then be determined by how the implant is rotationallypositioned in the storage unit in relation to the at least one referencefeature of the storage unit.

In embodiments, the detection of the at least one implant positioningmark in relation to the at least one reference feature when placing theimplant in the storage unit is performed by a vision and/or sensorsystem comprising at least one camera and/or sensor. The vision and/orsensor system may thereby be used for facilitating the correct placementof the implant in the storage unit.

In embodiments, at least one of the steps of gripping the implant in thestorage unit, removing the implant from the storage unit and theinserting the implant in the human joint (in a correct placementorientation) may be performed by the use of at least one mechanical arm,e.g. a robot arm. The step of inserting the implant in the correctplacement orientation in the recess of the joint may then be determinedby how the implant is rotationally positioned/oriented in the storageunit in that the software-controlled movement of the mechanical arm fromthe storage unit to the recess is pre-programmed based on the rotationalpositioning/orientation of the implant in the storage unit.

In embodiments, the technology disclosed relates to a storage unit forstoring an implant prior to inserting the implant in a human such as ahuman joint. The storage unit may then be provided with at least onereference feature, such as a positioning mark, which is adapted to beused for providing a correct or more accurate rotational orientation ofthe implant when placing the implant in the storage unit.

The implant may then be placed in the storage unit by directing at leastone implant positioning mark on the surface of the implant in aspecific, e.g. pre-determined, rotational direction in relation to atleast one reference feature of the storage unit. In certain embodiments,the implant is placed in the storage unit by directing at least oneimplant positioning mark in the direction of a reference feature, e.g. acorner, edge or holding means of the storage unit, e.g. a box, or apositioning mark provided on the surface of the storage unit.

The storage unit may further be adapted to allow for gripping of theimplant in the storage unit so that the implant is rotationally orientedin accordance with a specific rotational direction of the at least oneimplant positioning mark in relation to the at least one referencefeature or holding means of the storage unit. The design and location ofthe at least one implant positioning mark on the surface of the implantmay then be dependent on the design and location of the at least onereference feature of the storage unit.

In embodiments, the storage unit may be configured so that at least oneof the steps of gripping the implant in the storage unit, removing theimplant from the storage unit and inserting the implant in the humanjoint may be performed by use of at least one mechanical arm, e.g. arobot arm. The software-controlled movement of the mechanical arm fromthe storage unit to the recess may then be pre-programmed based on therotational positioning/orientation of the implant in the storage unitand the rotational placement orientation of the implant in a recess of ahuman joint may then be determined by how the implant is rotationallypositioned in the storage unit in relation to the at least one referencefeature of the storage unit.

In another embodiment, the present invention relates to an individuallydesign of surgical kit and/or a guide tool 12 comprising position marksand to a design method for design of such a kit.

In one embodiment, the placement of the position mark is determined byfirst determine the size, spread and placement of the cartilage contactsurface in a computer model and then use this model of a cartilagecontact surface and determine a direction, based on the virtualplacement of the model cartilage contact surface on the simulated joint(or on an image of an individual 3D image of a joint surface). And afterdeciding the direction, place a virtual position mark on that place,which may be a place pointing in any direction in comparison to theplacement of the guide tool in the joint, for example pointing in ananterior direction etc. The position mark is designed to be placed on asurface of the positioning body of the guide tool 12 which is a surfacepointing in an opposite direction compared to the cartilage contactsurface of the positioning body. The said placement of the positioningmark 500 is also determined in relation to the design of the guidechannel 54 and its placement on the cartilage contact surface 50 of theguide tool 12.

This placement of said position mark on the guide tool 12 may then beused by the surgeon in order to place the individually designed guidetool in the right placement during surgery by knowing in which directionthe positioning mark 500 is designed to point.

For example, if a guide tool 12 is designed to point in an anteriordirection during knee surgery, and the guide tool 12 then has apositioning mark 500, placed for example on a side or on top of theguide channel or on a top surface 52 of the positioning body 12. Thenthe surgeon knows that the positioning mark 500 should point in ananterior direction if he placed the guide tool in a correct direction,see for an example in FIG. 2 for a placement of an implant comprising apositioning mark 500 in an anterior direction in relation to the kneejoint.

A further effect of the invention is that the size of the cartilagecontact surface can be designed to be smaller in area spread because thesurgeon now know due to the positioning mark if the guide is placed inthe correct position from start and does not need a large cartilagecontact surface of the guide tool to “feel” when the guide is placedcorrectly.

In other embodiment, the design of the insert tools are also designed tocomprise a position marking and the position marking of the insert toolsis designed to coincide with the positioning mark of the guide tool 12when the insert tools are placed within the guide tool in their firstpositions or their starting position. This alignment gives instructionto the surgeon about rotational start direction when using the inserttools 502.

This is exemplified in FIG. 6 wherein a height adjustment device is usedas an insert tool 502 and in FIG. 6, the insert tool is placed in astarting position where both the positioning mark 500 of the insert toolis aligned with the positioning mark 500 of the guide tool 12.

See for example FIG. 2 for further examples of the invention where theimplanted implant has a position mark pointing in an anterior directioncompared to the joint and limb. The positioning mark 500 on the guidetool 12 used during placement of this implant also pointed in the samedirection, se for example in FIG. 5.

FIG. 4-10 shows use of the guide tool of the invention together withdifferent insert tools, FIG. 4a shows the guide tool without inserttools. FIG. 4b shows use of a drill guide 8 inside the guide channel 54of the guide tool 12.

FIG. 5 shows the guide tool 12 together with a height adjustment device16 inside the guide channel. A height adjustment device 16 according tothe invention comprises a male part 47 and a female receiving part 48which when used together allows for stepwise adjustment of drill depth.

In one embodiment the present invention comprises a design method fordesign of a surgical kit where one part is related to the design of aguide tool according to the present invention described herein and onepart is directed to the design of insert tools 502 comprisingpositioning marks 500 which is aligned with the positioning marks of thedesigned guide tool when inserted in the guide tool 12 in a startposition which indicating the correct rotational start position of theinsert tools to the surgeon during use of the guide tool and inserttools during surgery.

FIG. 11 shows a medical implant comprising a positioning mark accordingto the invention and wherein the direction of the positioning mark ofthe implant also is indicated on the cartilage surface due to previousguidance using the guide tool according to the invention during surgery.

The present invention concerns a guide tool 12 which is designed tocomprising a cartilage contact surface 52 which is individually designedto correlate to a surface and curvature in the joint. Due to this theguide tool 12 according to the invention may be correctly placed in thejoint in one predetermined direction. The direction is determined duringthe design of the guide tool 12.

This predetermined direction may now be easier to visually see for thesurgeon when he receives a guide tool according to the invention,designed to have a predetermined positioning mark, indicating apredetermined position instructing the surgeon about how he should placethe guide tool 12 on the cartilage surface in the joint.

I. Determining Physical Parameters for a Cartilage Damage in a Joint.

An image or a plurality of images representing a three dimensional imageof a bone member of the joint in a patient's limb may be obtained by aselected one of a per se known imaging technology for non-invasiveimaging of joints, such as magnetic resonance imaging (MRI),computerized tomography (CT) imaging or a combination of both, or othersuitable techniques such as delayed Gadolinium-enhanced MRI of cartilage(dGEMRIC) techniques. The image of the joint should comprise arepresentation of cartilage in the joint as well as the underlyingsubchondral bone in the area of the cartilage damage. Image data makingup a three dimensional image representation of the joint is stored in adigital format in a manner that enables to keep track of the dimensionsof the real joint that the image depicts.

The image data is analyzed in a data processing system to identify anddetermine physical parameters for the cartilage damage. The physicalparameters to determine comprise the presence, the location and the sizeand shape of the cartilage damage, as well as curvature of the surfacecontour of the cartilage or the subchondral bone in an area of thecartilage damage.

In one embodiment of the inventive concept the design system operates todetermine physical parameters on images of the patient's individualjoint and the current cartilage damage, and thereby produces anindividually designed guide tool 12. In another embodiment the designsystem operates on a collection of images of joints constituting astatistical basis for determining physical parameters for producing aguide tool 12 adapted for a selected location and a selected size ofcartilage damage in a joint of a selected size.

The following steps, not limiting the design method according to theinvention are in one exemplifying embodiment comprised in determiningthe physical parameters of cartilage damage:

-   a. Obtaining image data representing a three dimensional image of a    bone member of the joint. By way of example, a sample of a set of    several images which together represents a three dimensional image    of a joint.-   b. Identifying in the image data cartilage damage in an articulating    surface of the bone member. In an automated process a computer    program may be adapted to scan the image data for predetermined    characteristics of a spot of cartilage damage in the image data. In    a process with a manual part in this step an operator would visually    scan a displayed image of the joint and identify a spot that has the    visual characteristics of cartilage damage.-   c. Determining based on the image data the location of the cartilage    damage.    -   A set of data that represents a position of the cartilage damage        in the joint is selected automatically or manually. The position        data is for example stored as a set of defined coordinates in        the image data.-   d. Determining based on the image data the size and shape of the    cartilage damage.    -   Selected measurements for size and shape of the cartilage are        calculated in the image date, for example by determining a        boundary line for the healthy cartilage surrounding the        cartilage damage. A circular cross-section shape is preferably        selected such that it covers the cartilage damage with a        perimeter at a predetermined safe distance from the fringes of        the damaged cartilage. The size and shape data is for example        stored as a set of perimeter and thickness data with a        predetermined resolution.-   e. Determining based on the image data the surface contour curvature    of the cartilage and/or the subchondral bone in the joint in a    predetermined area comprising and surrounding the site of cartilage    damage.    -   The curvature of the surface contour is determined for example        by per se known surface matching methods in image processing.        The determined curvature information can be represented as an        equation or as a set of image data. The determined curvature        preferably comprises two subsets of curvature information.        Firstly, one subset comprises the curvature of the contour        portion that comprises the cartilage damage within the        cross-section shape defining the selected boundary line for the        area covering the cartilage damage. Secondly, the second subset        comprises the curvature of a contour portion that surrounds the        site of cartilage damage, preferably comprising mutually        opposing sloping parts.

II. Generating Design Parameters for a Medical Implant (10).

Based on the physical parameters for the cartilage damage, designparameters for an implant are generated by processing the physicalparameters in a design stage 95 according to a predetermined scheme forthe shape of an implant in the specific surgical application.

The shape and size of the implant are calculated or selected dependenton the size and shape of the cartilage damage, and dependent on thecurvature of the contour of the cartilage and/or of the subchondral bonein the area substantially coinciding with the cartilage damage,optionally a positioning mark is added to the articulating surface ofsaid implant which indicate rotational positioning to the surgeon. Thepositioning mark 500 of the implant 10 may for example point out adirection in relation to the joint axis 501 or other anatomic dependentdirection and may point out same direction as the positioning mark onthe guide tool 12 used for placing said implant.

The following steps are in one non limiting exemplified embodiment ofthe design method of the invention comprised in generating designparameters for a medical implant 10:

-   f. Generating the contour curvature for an articulating surface of    an implant body 27 dependent on said determined surface curvature of    the cartilage and/or the subchondral bone.    -   The contour curvature for the articulating surface of the        implant body is generated to correspond to the curvature that        covers the cartilage damage.-   g. Generating a cross-section for the implant body dependent on and    substantially corresponding to said determined size and shape of the    damaged cartilage.    -   The cross-section for the implant body is generated to        correspond to the cross-section shape determined for the        cartilage damage.-   h. Generating an edge height 14 for the implant body that    substantially corresponds to the thickness of healthy cartilage plus    a selected height of a bone contacting part of the implant for    countersinking the implant into a recess to be made in the bone to    fit and receive the implant.    -   A first part of the edge height 14 for the implant body 27 is        generated to correspond to the determined height of the healthy        cartilage, and a second part corresponds to a countersink height        selected automatically according to a predetermined scheme or        selected manually by an operator.-   i. Optionally generating a length and a cross-section profile for an    extending post 23 extending from a bone contacting surface of the    implant dependent on predetermined rules related to the size and    shape of the cartilage damage.    -   The size and shape of the extending post is selected        automatically according to a predetermined scheme or is selected        manually by an operator.    -   The image based tool may also be configured for using        predetermined shapes that are adapted to the determined physical        parameters to automatically or manually fit to the cartilage        damage and thereby generate the design parameters.

Generating design parameters for a guide tool 12 for implanting theimplant.

The design parameters for the guide are generated dependent on thephysical parameters for the cartilage damage and/or dependent on thedesign parameters for the medical implant.

The following steps are in one exemplified embodiment of the inventioncomprised in generating design parameters for a medical implant:

-   j. Generating the contact points for a cartilage contact surface 50    of a positioning body 11 dependent on said determined surface    contour curvature of the cartilage and/or the subchondral bone in    the joint in a predetermined area comprising and surrounding the    site of cartilage damage, such that said cartilage contact surface    50 of the positioning body corresponds to and fits to said surface    contour of the cartilage or the subchondral bone in the joint.-   k. Generating the cross-section profile for a guide channel 54 in a    guide body 13 extending from the positioning body, said guide    channel 54 passing through said positioning body 11 and said guide    body 13,    -   the cross-section profile for the guide channel being generated        dependent on and substantially corresponding to said determined        size and shape of the damaged cartilage, and    -   such that the guide channel 54 is designed to have a        cross-sectional profile that corresponds to the cross-section of        the plate shaped implant body 27,    -   and such that the guide channel 54 is designed to have a muzzle        29 on the cartilage contact surface 50 of the positioning body        at a position corresponding to the site of the diseased        cartilage.

In further exemplifying embodiments inserts tools intended to be usedinside the guide channel 54 may comprise positioning marks pointing insame direction as positioning mark on the guide tool 12;

Comprising of generating the cross-section profile for an insert tool tohave a cross-sectional profile that corresponds to the cross-sectionalprofile of the guide channel 54 with a tolerance enabling the inserttool 8 to slide within the guide channel 54 further comprising apositioning mark pointing in same direction as the positioning mark onthe guide tool 12.

Further Exemplified Embodiments of Design of Insert Tools;

Embodiments of the invention further comprise optional combinations ofthe following:

Generating design parameters for a drill bit 2 dependent on the designparameters for the extending post and such that a cross-sectional areafor a drill bit is slightly smaller than the cross-sectional area forthe extending post 23. Wherein the drill bit 2 is designed to comprisepositioning marks pointing in same direction as the positioning markpresent on the guide tool 12.

Generating design parameters for a cartilage cutting tool 6, 105 with across-sectional profile that is designed to correspond to thecross-sectional profile of the guide channel 54 with a toleranceenabling the cartilage cutting tool 6, to slide within the guide channel54. Wherein the cutting tool is designed to comprise positioning markspointing in same direction as the positioning mark present on the guidetool 12 indication in which rotational direction the cartilage cuttingtool 6 should enter the guide channel 54 of the guide tool 12.

Generating design parameters for the implant comprises generating designparameters for an implant body 27 of the implant 10 being substantiallyflat, having a thickness 14 of approximately 0.5-5 mm.

Generating design parameters for the positioning body comprisesgenerating design parameters for the cartilage contact surface of thepositioning body having three contacting points 40, 42, 44, spread outaround the guide body 13, for contacting parts of the joint in order toprovide stable positioning of the guide tool 12 in the joint. Optionallydesigning the placement of the positioning mark on top said positioningbody, so that the surgeon easily may see the mark during usage of theguide tool and wherein the positioning mark may point out a directionfor placement of the guide tool in the joint in relation to the jointaxis 501 or other anatomic dependent direction and may point out samedirection as the positioning mark on the guide tool 12 used for placingsaid implant.

Generating design parameters for the guide channel 54 to have a height31 of 3-10 cm.

Generating design parameters for the guide channel comprises generatingdesign parameters for an orifice leading through the guide body 13 atthe foot of said guide body.

Generating design parameters for a hammer tool 35 with a cross-sectionalprofile that is designed to correspond to the cross-sectional profile ofthe guide channel 54 with a tolerance enabling the hammer tool 35 toslide within the guide channel 54.

Details of the Surgical Kit The Implant Structure

FIG. 3a-3b shows a medical implant 10 of a surgical kit according to anembodiment of the inventive concept. The plate shaped implant body 27has an articulating surface (first surface) 15 configured to face thearticulating part of the joint and a bone contact surface (secondsurface) 21 configured to face bone structure in the joint, the plateshaped implant body 27 has a cross-section that substantiallycorresponds to the area of the damaged cartilage and the articulatingsurface 15 has a curvature that substantially corresponds to thecurvature of a healthy articulating surface at the site of diseasedcartilage. The extending post 23 extends from the bone contact surface21. Since the implant 10 of the inventive concept is custom made for aspecific patient, FIG. 3a-b is an exemplifying schematic picturedisplaying one embodiments of the implant 10. Between the articulatingsurface 15 and the bone contact surface 21 there is a cartilagecontacting surface 19.

The implant is specially designed, depending on the knees appearance andthe shape of the damage and in order to resemble the body's own parts,having a surface which preferably corresponds to a three dimensional(3D) image of a simulated healthy cartilage surface. The implant will betailor-made to fit each patient's damaged part of the joint.

Implant Body

The implant body 27 is substantially plate shaped, meaning that theshortest distance (represented by 24 in FIG. 3) crossing the surface 15of the implant body 27 is substantially larger, e.g. at least 1.5 timeslarger than the thickness 14 of the implant body 27. By substantiallyplate shaped is meant that the implant body 27 may be substantially flator may have some curvature, preferably a 3D curvature of thearticulating surface 15. The articulating surface 15 may for examplehave a curvature that corresponds to a simulated healthy cartilagereconstructed from an image taken e.g. with MRI or CT-scanning of thedamaged cartilage surface of the joint. Once the implant 10 is placed inthe joint there will be a surface with no parts of the implant pointingup from or down below the surrounding cartilage—the implant isincorporated to give a smooth surface.

The area and the shape of the implant surface 15 are individualdepending on the size of cartilage damage and location of the cartilagedamage. The area and shape of the implant can be decided by the surgeonhimself or be chosen from predetermined shapes. For instance thecross-section of the implant body 27 may have a circular or roughlycircular, oval, triangular, square or irregular shape, preferably ashape without sharp edges (see FIG. 8 a-b and implant 10). The implanthead or implant body 27 can vary in size and shape and are adjusted tothe size and shape of the damaged cartilage tissue and to the needs ofparticular treatment situations. The size of the implant 10 may alsovary. The area of the articulating surface 15 of the implant varies indifferent realizations of the inventive concept between 0.5 cm² and 20cm², between 0.5 cm² and 15 cm², between 0.5 cm² and 10 cm², between 1cm² and 5 cm² or preferably between about 0.5 cm² and 5 cm².

In general, small implants are preferred since they have a smallerimpact on the joint at the site of incision and are also more easilyimplanted using arthroscopy or smaller open surgical procedures. Theprimary factor for determining the size of the implant is however thenature of the lesion to be repaired.

The Extending Post

The implant replaces an area of damaged cartilage in an articulatingsurface of a joint. Before the implant is placed in the desiredposition, the damaged cartilage is removed and also a part of the bonebeneath, i.e. a recess fitting the implant is made in the bone.Furthermore, a hole can be drilled in the bone to fit the implantstructure. The extending post of the implant or the rod-part 23 of theimplant 10, is used for securing the implant 10 in the drilled hole ofthe bone. The length 22 of the extending post 23, extending from theimplant head 27, is adjusted to a length needed to secure the implant 10in the bone. The extending post 23 is intended to give a primaryfixation of the implant 10, it provides mechanical attachment of theimplant 10 to the bone in immediate connection with the surgicaloperation.

The position of the extending post 23 on the bone contact surface 21 canbe anywhere on the bone contact surface 21 or the extending post 23 mayhave a central position.

The extending post 23 has a physical structure in the form of forexample a cylinder or other shapes such as one or more of a small screw,peg, keel, barb or the like.

In one embodiment, the extending post 23 has a positioning part 25,where the positioning part 25 is located distal to the plate shapedimplant body 27. The longitudinal symmetry axes of the first part of theextending post 23 and the positioning part 25 coincide. The diameter ofthe positioning part 25 is smaller than the diameter of the first partof the extending post 23.

The Guide-Tool

FIG. 13a-b shows exemplifying embodiments of a guide-tool 12. Otherexamples of guide tools according to the invention is The guide tool 12comprises a positioning body 11 and a guide body 13, with a guidechannel 54 through said guide body 13 and positioning body 11. Thepositioning body has a cartilage contact surface 50 that has a shape andcontour that is designed to correspond to and to fit the contour of thecartilage or the subchondral bone in the joint in a predetermined areasurrounding the site of diseased cartilage. The guide tool 12 also has atop surface 52 facing the opposite direction compared to the cartilagecontacting surface 50. The guide body 13 extends from said top surface52 of the guide tool 12.

The guide channel 54 has an inner cross-sectional profile that isdesigned to correspond to the cross-section of the plate shaped implantbody 10. In other words, the plate shaped implant body 10 fits the guidechannel 54, with a slight tolerance to allow a sliding movement of theimplant in the guide channel 54. The positioning body 11 has a mouth ormuzzle 29 which is the guide channel's 54 opening on the cartilagecontact surface 50. The mouth 29 is in a position on the cartilagecontact surface 50, corresponding to the site of the diseased cartilagein a joint. The height 31 of the guide channel 54 must be sufficientlylong to give support to the tools used inside the guide body 13. Theheight 31 is preferably higher than the thickness of the surroundingtissue. In this way, the opening of the guide channel 54 is easy toaccess for the surgeon. The height 31 of the guide channel 54 is between1 and 10 cm, preferably 3-10 cm, and always sufficiently high to ensurestabilization of the tools that are to be inserted into the guidechannel 54.

The guide tool 12 is easy to place due to the precise fit of thepositioning body 11 on the cartilage surface. The guide tool 12 isdesigned to be inserted in as lesion which is as small as possible to beable to repair the specific cartilage damage. The height 31 of the guidechannel 54 is sufficiently high to be easily accessible for the surgeonduring surgery. In one embodiment, the top of the guide channel 54 isdesigned to project above the tissue surrounding the surgery cut whenthe guide tool is placed on the cartilage in a joint during surgery.

The size and shape of cartilage contact surface 50 of the guide tool 12is determined depending on the size and shape of the damaged cartilageand thus on the cross section of the implant body 10 and the guidechannel 54, and also depending on the position of the cartilage area ina joint. The size, shape or spread of the surface 50 is a considerationbetween the following aspects; minimize surgery lesion, maximizestability for guide tool 12, anatomic limitations on the site of theinjury. Not all cartilage surfaces in a joint can be used for placementof the guide tool. A large spread of the cartilage contact surface 50 isto prefer to get good stability of the guide tool, however, a largesurface area of the surface 50 may also lead to a large surgicalintervention which is undesired. Thus the size of the cartilage contactsurface 50 and of the positioning body 13 is determined by a balancebetween the desire to achieve good positioning stability and smallsurgical operations. Also, the cartilage contact surface 50 need nothave a continuous, regular shape, but may have an irregular shape, aslong as it gives adequate support and stable positioning of the guidetool 12. The cartilage contact surface may also consist of threeseparated points.

When designing the guide tool, the cartilage contact surface 50 can bedesigned to cover three points (40, 42, 44 for an example, see FIG. 13b) distributed over the cartilage surface of the joint where the implantis to be inserted. The points are chosen to give maximum support andpositional stability for the positioning body 11 and thus these points,either decided and identified by the surgeon or automatically identifiedby design software, serve the ground when designing the surface 50 ofthe guide tool 12. The cartilage contact surface 50 can also be formedsuch that it uses the curvature in the cartilage surface in a joint forstability. For example, in a knee joint, the condyles are separated fromeach other by a shallow depression, the posterior intercondyloid fossa,this curvature together with the medial epicondyle surface can be usedto give the cartilage contact surface 50 a stabile attachment to thecartilage surface in a knee joint. The cartilage contact surface doesnot need to be a continuous, regular surface but preferably has thethree points exemplified by 40, 42 and 44 for stability. Optionally thecartilage contacting surface 50 can be further stabilized by attachmentwith nails, rivets or similar attachment means to the bone surroundingthe cartilage in a joint (see FIG. 4b ). This additional attachment withrivets 48 or the like gives additional support and stability and alsogives the possibility to keep the cartilage contact surface as small aspossible. The position of the rivets may be predetermined and marked outon the surface 50 by premade drill holes 33.

The guide-tool 12 aids with exact precision removal of a volume ofcartilage and subchondral bone and the guide tool 12 also guides theplacement of the implant 10 in for example a knee. Placement of anexemplified embodiment of the guide-tool 12 on the cartilage surface ona knee can be seen in FIG. 13 a.

The guide body 13 comprises an orifice, see FIG. 11, at the foot of theguide body that leads from the guide channel into the open outside theguide body. The orifice 145 is designed to enable output of waste suchas cartilage tissue and bone chips from boring or reaming in thepreparation of the recess for the implant in the joint. The orifice ispreferably also designed to enable visual inspection into the implantsite during surgical operation.

The guide tool according to the present invention is further designed tocomprise a positioning mark 500, comprised in the structure of thepositioning body or guide body or guide channel construction of theguide tool and wherein the positioning mark is aligned with the center503 of the guide channel 54 in a chosen joint axis 501 direction.

The guide tool 12 may be placed in the joint using pins 506 and clamps507 for stabilization and fastening see for example in FIG. 7.

The Insert Tool 502

The insert tool 502 is in different embodiments of the invention forexample selected from; the cartilage cutting tool, the punch, thecartilage cut drill, the reamer guide, the drill guide or the hammertool, implant dummy, cartilage cutter. The insert tool is used insidethe guide channel 54 of the guide tool 12 and fits in the guide channel54, with a slight tolerance to allow a sliding movement of the inserttool in the guide channel 54. The cross-sectional profile, and thus thecircumferential shape of the insert tool, corresponds to the chosencross-section of the implant surface 15 in size and shape

The Cartilage Cutting Tool

The cartilage cutting tool is a tool which is used to cut the cartilagein the joint around the area of damaged cartilage to prepare for theinsertion of the implant. The cartilage cutting tool may for example bea punch 6 or a cartilage cut drill 105. It is used inside the guidechannel 54 of the guide tool 12 and fits in the guide channel 54, with aslight tolerance to allow a sliding movement of the cartilage cuttingtool in the guide channel 54. The cartilage cutting tool preferably cutsthe cartilage so that the cut edges of the cartilage are sharp andsmooth. These sharp and smooth edges are of great importance when theimplant is placed into the prepared recess in the cartilage and bone. Inone embodiment the cartilage cutting tool, in addition to cutting thecartilage, may also cut/carve/drill the underlying bone. A hole in thecartilage which is cut (punched or drilled) with the cartilage cuttingtool according to the inventive concept ends up with a precise fit ofthe implant into the prepared cartilage since the cartilage cutting toolallows for an exact, precise cut. The recess in the cartilage and/orbone, made by the cartilage cutting tool always correspond to the chosencross-section of the implant surface 15 in size and shape

In one exemplifying embodiment of the inventive concept the cartilagecutting tool is a punch 6. The punch 6 is a solid body with a hollowshape or recess 5 in one end. The recess 5 has sharp edges 60. The punch6 is used to punch out and remove the damaged cartilage from the joint.The punch is to be placed inside the guide channel 54 of the guide tool12, with the recess pointing down onto the cartilage. A hammer is thenused to hammer the punch recess 5 through the cartilage. In this way thedamaged cartilage is removed by punching. The depth 59 of the recess 5on the punch 6 may be adjusted to the individual person's cartilagethickness. It is of great importance that the punch has sharp cuttingedges 60.

The punch 6 fits the inside of the guide channel 54, with a slighttolerance to allow a sliding movement of the punch in the guide channel54. The fit ensures the correct, desired placement of the punch on thecartilage surface and thus the precise removal of the damaged cartilagearea.

The punch preferably gives sharp precise edges of the remainingcartilage in the joint surrounding the removed cartilage piece, which isof importance when placing the implant 10 in the joint. The contour ofthe cutting edge 60, i.e. the contour of the surface of the cutting edge60 that is to face and cut the cartilage, is in one embodiment designedto match the contour of the patient's cartilage and/or bone at the siteof the joint where the punch is to cut. This further ensures that thecartilage will be properly and efficiently cut, giving sharp preciseedges of the remaining cartilage as well as minimized damage to theunderlying bone.

The length 56 of the punch 6 is in one embodiment longer than the height31 of the guide channel 54. The length 56 of the punch 6 is preferablybetween 4 and 12 cm.

The cross-sectional profile, and thus the circumferential shape of thecutting edge 60, of the punch 6 corresponds to the chosen cross-sectionof the implant surface 15 in size and shape The cross-sectional profileof the punch varies in different realizations of the inventive conceptbetween 0.5 cm² and 20 cm², between 0.5 cm² and 15 cm², between 0.5 cm²and 10 cm² or preferably between about 1 cm² and 5 cm².

In one exemplifying embodiment of the inventive concept the cartilagecutting tool is a cartilage cut drill. The cartilage cut drill is usedto cut the cartilage in the joint around the area of damaged cartilageto prepare for the insertion of the implant with a cut-drill technique.

The cartilage cut drill 105 is a drill, with a drill body 111 and withsharp cutting edges 108 and a center marker 106. The cartilage cut drill105 has a cross-sectional profile that is designed to correspond to theinner cross-sectional profile of the guide channel 54 with a toleranceenabling cartilage cut drill body 111 to slide within the guide channel54. Also, the cross-sectional profile is designed to correspond to thecross-section of the implant.

The Reamer Guide

In one embodiment of the inventive concept the surgical kit comprises areamer guide that is placed in the guide channel 54 before reaming therecess in the bone. The reamer guide placed in the guide channel 54protects the cartilage surrounding the implant site while the reamer bit4 is used inside the guide channel 54 of the guide tool 12.

The reamer guide 28, is a channel shaped structure with thin wallsdesigned to fit the inside of the guide channel 54, with a slighttolerance to allow a sliding movement of the reamer guide 28 in theguide channel 54. In other words, the cross-sectional profile of thereamer guide 28 fits the cross sectional profile of the guide channel 54such that the reamer guide 28 may be used as a lining, lining theinsides of the guide channel 54 (see FIG. 8). The walls of the reamerguide 28 have a thickness of less than 1 mm. The reamer guide 28preferably has a height 66 that is at least the height achieved byadding the inner height 31 of the guide channel 54 with the height 59 ofthe recess 5 of the punch 6.

The Height Adjustment Device or Insert Tool

A height adjustment device 16 according to the invention comprises amale part 47 and a female receiving part 48 which when used togetherallows for stepwise adjustment of drill depth.

The male part is in the outermost position in a zero-mode and may fromthere be adjusted inwards allowing the surgeon stepwise the for examplemake stepwise deeper drill holes. When the height adjustment device 16is in starting mode or outermost zero-mode the positioning marking ofthe guide tool 12 and the positioning marking of the height adjustmentdevice are aligned, se for example FIG. 6.

Thus, by being able to adjust the length 31 of the guide channel thesurgeon is also able to adjust the depth of drilling and cutting intothe bone. The length 31 of the guide channel may be varied since theguide body 13 and the height adjustment device 16 parts are able to movein relation to one another. Further, the male part 47 and the femalereceiving part 48 of the height adjustment device may be arranged suchthat the length 31 of the guide channel may be varied at certainstepwise intervals 115, e.g. at 200 μm or at 100-300 μm intervals orsteps, or any other desired interval, see for example FIG. 16. Forexample, the height might be adjusted between for example 0.2-3 mm, inone or several steps. This may for instance be achieved by arranging themale part 47 inside the female receiving part 48 of the heightadjustment device 16 such that the male part 47 insert tool to have across-sectional profile that corresponds to the cross-sectional profileof the female part guide channel 120 with a tolerance enabling theinsert tool to slide within the guide female part guide channel 120. Forexample, the construction may be arranged such that the guide body 13and height adjustment device 16 may be turned in relation to one anotherat preset steps, by lifting the male part sot that the protruding ridgesmay slip out of one groove and enter another groove. When the male part47 is fitted in the female part their position are locked in relation toeach other or prone to hook each other at those intervals. The femalepart comprises grooves or ledges 17 at different heights relative to thepositioning body of the guide tool. The male part 47 comprises a guidechannel 54 inside the male part 47, the guide channel 54 may be cylindershaped and protruding ridges 105 on the outer surface of the male part47. When the male part 47 is placed inside the female receiving part 48the protruding ridges 105 of the male part 47 are placed or locatedinside one of the grooves 17 on the female receiving part 48. Theposition of the grooves 17 and the position of the ridges 105 inrelation to the positioning body or the cartilage contact surface 50adjust or regulate the length 31 of the guide body 13. The heightadjustment device 16 may be used by the surgeon to adjust the depth ofdrilling, e.g. by increasing the drill depth in steps at the presetintervals. The height adjustment device 16 may advantageously be usedtogether with an implant dummy 36, as described below, to make sure thatthe drill depth in the bone matches the height 14 of the implant body27. This ensures that the articulating surface 15 of the implant 10 willbe in line with the surrounding cartilage at the site of implantationonce implanted.

The Drill-Guide,

In one embodiment of the inventive concept the surgical kit comprises adrill guide 8 that is used to direct a drill for drilling a hole in thebone at the site of cartilage damage, for fastening of the extendingpost 23 of the implant 10 in the bone tissue. The drill guide 8comprises a drill guide body and a guide channel 7 passing through thedrill guide body. The guide channel 7 is designed to receive and guidethe drill during the surgical procedure. The drill guide 8 is designedto fit the inside of the guide channel 54, with a slight tolerance toallow a sliding movement of the drill guide 8 in the guide channel 54,see FIG. 8a-b . In other words, the cross-sectional profile of the drillguide body matches the cross-sectional profile of the guide channel 54The fit ensures the correct, desired placement of the drill guide 8 onthe cartilage surface and thus ensures the precise direction andplacement of the drill hole in the bone.

The guide channel 7 is designed to be positioned in the drill guide bodysuch that the position corresponds to the desired position of the drillhole in the bone. The positioning of the guide channel 7 in the drillguide 8 is coordinated with the positioning of the extending post 23 onthe bone contacting surface 21 of the implant to ensure correctpositioning of the implant in the bone.

The length 62 of the drill guide 8 and thus the drill channel 7 islonger than the height 31 of the guide channel 54. The length ispreferably 4-12 cm.

The cartilage contacting surface 64 of the drill guide 8 corresponds tothe chosen implant surface 15 in size and shape. The surface 64 variesin different realizations of the inventive concept between 0.5 cm² and20 cm², between 0.5 cm² and 15 cm², between 0.5 cm² and 10 cm² orpreferably between about 1 cm² and 5 cm². In one embodiment thecartilage contacting surface 64 of the drill guide 8 is designed tomatch the contour of the patient's cartilage and/or bone at the site ofthe joint where the implant is to be inserted.

See FIG. 9c for a demonstration of how the drill-guide 8 fits inside theguide-channel 54 of the guide-tool 12.

Drill-Bit

The surgical kit of the present inventive concept may also comprise adrill-bit 2, see FIG. 12. The drill-bit 2 may have an adjustable depthgauge 1. The depth gauge 1 on the drill-bit 2 is supported by the top 30of the guide channel 54 and by using this support the depth of the drillhole can be controlled. The drill-bit 2 fits inside the drill channel 7in the drill-guide 8 to give a drill-hole in the bone with an exactposition and depth and where the depth is depending on the placement ofthe depth gauge 1 on the drill-bit 2, and also depending on the heightof the guide-channel 31.

Reamer-Bit

The surgical kit of the present inventive concept may also comprise areamer-bit. The reamer-bit 4 may have a depth gauge 3. The reamer bit 4is used together with the guide-tool 12 and possibly the reamer guide28. The reamer-bit 4 is used inside the guide channel 54, removing bonetissue, aided by the guide channel 54 and possibly the reamer guide 28.The depth gauge 3 on the reamer-bit 4 is supported by the top 30 of theguide channel 54 and by using this support the depth of the reamed bonerecess can be controlled. The depth of the reamed recess in the bone isdepending on the placement of the depth gauge 3 on the reamer-bit 4, andalso depending on the height 31 of the guide-channel 54. The depth ofthe reamed surface is determined depending on the injury and on thedesired implants size.

Hammer Tool

The optional hammer tool 35 (see FIG. 12) consists of a solid body andis designed to fit the inside of the guide channel 54, with a slighttolerance to allow a sliding movement of the hammer tool 35 in the guidechannel 54, see FIG. 8. The hammer tool 35 is used inside the guidechannel 54 to hammer the implant in place. The height of the hammer tool68 is the same height 62 as of the drill guide 8. Once the hammer toolis hammered in the same level as the top of the guide channel, thehammering and thus the placement of the implant is finished.

Implant Dummy and Dummy Reference

The implant dummy 36 and dummy reference 37, see FIG. 12, are used tomake sure that the cut, carved or drilled recess in the bone that is toreceive the implant body 27, is deep enough to fit the implant. This isvery important, since the articulating surface 15 of the implant 10 mustnot project over the surface of the surrounding cartilage tissue. If itwould it could cause a lot of damage to the surrounding cartilage and tothe cartilage on the opposite side of the joint. Preferably thearticulating surface 15 should form a continuous surface with thesurrounding cartilage, neither projecting above nor being sunken belowthe surface of the surrounding cartilage. The checking of the recessdepth is difficult or impossible to do with the implant 10 itself, sincethe implant 10, e.g. with its extending post 23, is designed to be fixedin the bone once inserted, and thus is difficult or impossible toremove. The implant dummy, on the other hand, is designed for easyremoval from the recess once the recess depth has been checked.

The implant dummy 36, see FIG. 12, has an implant element 41 that isdesigned to match the implant body 27. The lower surface 41 a of theimplant element 41 is a replica of the bone contact surface 21 of theimplant that is to be implanted. That is, if the implant 10 and bonecontact surface 21 is custom made for the specific patient, the implantelement 41 and its lower surface 41 a will also be custom made and thelower surface 41 a be a replica of the bone contact surface. Thecross-sectional profile of the implant element 41 corresponds to thecross-sectional surface of the implant body, or is slightly smaller inorder to ensure easy removal of the implant dummy from the recess.

The implant dummy 36 also has a top surface. The distance between thelower surface of the implant element 41 and the top surface correspondsto the distance that you get when adding the thickness 14 of the implantbody 27 (corresponding to the depth of the recess in the bone plus thethickness of the corresponding cartilage). The dummy reference 37, seeFIG. 12, is arranged to fit to, and possibly releasable attach to, theguide hole 53 of the guide base 12, see.

To ensure that the implant dummy 36 is placed in a correct orientationin the recess of the bone, i.e. in an orientation that corresponds tothe orientation that the implant 10 is to be inserted in, the topsurface 43 and/or the implant element 41 may be provided withpositioning mark 500. A corresponding positioning mark 500 is providedalso on the implant dummy 36 and on the guide base 12.

A Medical Implant Comprising at Least Two Substantially Circular Shapes

FIGS. 14a and 14b show a medical implant 1410 according to the inventionwhich comprises two substantially circular shapes 1411 where one of thecircular shapes is provided with a positioning mark 1420 on itsarticulating surface 15.

The positioning mark 1420 on the articulating surface 15, i.e. the topsurface 15 facing the articulating part of the joint, of one of thecircular shapes of the medical implant illustrated in FIGS. 14a and 14bis designed to be used for determining the orientation in which theimplant is to be placed in a recess made in a damaged articulatingsurface of a joint.

The positioning mark 1420 on the articulating surface 15, i.e. the topsurface 15 facing the articulating part of the joint, of one of thecircular shapes of the implant illustrated in FIGS. 14a and 14b may bedesigned so that the direction of the positioning mark 1420 isdetermining the placement orientation of the implant in a recess in thatthe placement orientation of the positioning mark is also to beindicated by a mark made on the side of a recess made in thearticulating surface of a joint in which the implant is to be inserted,thereby providing for a correct or more accurate orientation of theimplant when inserted in the recess made in a damaged articulatingsurface of a joint.

The positioning mark 1420 on the articulating surface 15, i.e. the topsurface 15 facing the articulating part of the joint, of one of thecircular shapes of the implant 1420 illustrated in FIGS. 14a and 14b maybe designed so that the direction of the positioning mark is designed tobe pointing in an anatomic dependent direction in relation to a recessmade in the articulating surface of a joint in which the implant is tobe inserted, thereby providing for a correct or more accurateorientation of the implant when inserted in the recess made in a damagedarticulating surface of a joint.

FIGS. 15a and 15b shows a medical implant 1510 according to theinvention which comprises two substantially circular shapes 1511, e.g.designed from using a virtual model comprising two substantiallycircular shapes, where one of the circular shapes is provided with apositioning mark 1520 on its the cartilage contacting surface 19, i.e.its side edge surface 19.

The positioning mark 1520 on the cartilage contacting surface 19, i.e.the side edge surface 19, of one of the circular shapes of the medicalimplant illustrated in FIGS. 15a and 15b is designed to be used fordetermining the orientation in which the implant 1520 is to be placed ina recess made in a damaged articulating surface of a joint.

The positioning mark 1520 on the cartilage contacting surface 19, i.e.the side edge surface 19, of one of the circular shapes of the implantillustrated in FIGS. 15a and 15b may be designed so that the directionof the positioning mark 1520 is determining the placement orientation ofthe implant in a recess in that the placement orientation of thepositioning mark is also to be indicated by a mark made on the side of arecess made in the articulating surface of a joint in which the implantis to be inserted, thereby providing for a correct or more accurateorientation of the implant when inserted in the recess made in a damagedarticulating surface of a joint.

The positioning mark 1520 on the cartilage contacting surface 19, i.e.the side edge surface 19, of one of the circular shapes of the implantillustrated in FIGS. 15a and 15b may be designed so that the directionof the positioning mark is designed to be pointing in an anatomicdependent direction in relation to a recess made in the articulatingsurface of a joint in which the implant is to be inserted, therebyproviding for a correct or more accurate orientation of the implant wheninserted in the recess made in a damaged articulating surface of ajoint.

Storage Units for Storing a Medical Implant Prior to Inserting theImplant in a Human Joint

FIG. 16 shows a storage unit 1610 adapted for storing a substantiallycircular shaped medical implant 1612 prior to inserting the medicalimplant in a recess made in a joint. The storage unit 1610 illustratedin FIG. 16 comprises a plurality of reference features in the form of apositioning mark 1620, an edge 1621 and a corner 1622.

The storage unit 1610 illustrated in FIG. 16 further comprises both amechanical recess structure 1630 and holding means 1640 adapted forholding and positioning the implant 1612 in a rotationally fixedposition in the storage unit 1610.

The plurality of reference features 1620, 1621, 1622 of the storage unit1610 illustrated in FIG. 16 are adapted to be used for rotationallypositioning the substantially circular shaped implant 1612 in thestorage unit 1610 in that a positioning mark 1614 on the substantiallycircular shaped implant to be stored in the storage unit 1610 is usedfor rotationally positioning the implant 1612 in relation to theplurality of reference features 1620, 1621, 1622. The implant 1612 isthen placed in the storage unit 1610 by directing the implantpositioning mark 1614 on the surface of the implant in a specific, e.g.pre-determined, rotational direction in relation to at least one of theplurality of reference features of the storage unit.

FIG. 17 shows a storage unit 1710 adapted for storing a medical implantcomprising two circular shapes 1713 prior to inserting the medicalimplant 1712 in a recess made in a joint. The storage unit 1710illustrated in FIG. 17 comprises a plurality of reference features inthe form of a positioning mark 1720, an edge 1721 and a corner 1722.

The storage unit 1710 illustrated in FIG. 17 further comprises amechanical recess structure 1730 adapted for holding and positioning theimplant in a rotationally fixed position in the storage unit.

The plurality of reference features 1720, 1721, 1722 of the storage unit1710 illustrated in FIG. 17 are adapted to be used for rotationallypositioning an implant 1712 comprising the two circular shapes 1713 inthe storage unit 1710 in that a positioning mark 1714 on one of thecircular shapes 1713 is used for rotationally positioning the implant1712 in relation to the plurality of reference features. The implant isthen placed in the storage unit 1710 by directing the implantpositioning mark 1714 on the surface of the implant in relation to atleast one of the plurality of reference features of the storage unit,e.g. the implant positioning mark 1714 may be directed in the directionof the positioning mark 1720 on the upper surface of the storage unit1710.

1: A method for designing an implant, comprising: designing a contourcurvature of the implant so that an articulating surface of the implantis designed to correspond to a simulated healthy articulating surface ofa damaged articulating surface of a joint; providing at least twosubstantially circular shapes such that each of said substantiallycircular shapes is partly overlapping at least one other substantiallycircular shape; and providing at least one positioning mark on at leastone of said at least two substantially circular shapes such that said atleast one positioning mark is designed to be used for determining theorientation in which the implant is to be placed in a recess made in adamaged articulating surface of a joint. 2: The method according toclaim 1, further comprising providing at least one of said at least onepositioning mark on the articulating surface of one of said at least twosubstantially circular shapes. 3: The method according to claim 1,further comprising providing said at least one positioning mark on theside edge of one of said at least two substantially circular shapes. 4:The method according to claim 1, further comprising: designing thecontour curvature of the implant so that the articulating surface of theimplant corresponds to a simulated healthy articulating surfacereconstructed from a 3D model based on one or more images taken with MRIor CT-scanning of a damaged articular surface. 5: The method accordingto claim 1, further comprising: designing the contour curvature of theimplant to be patient customized in that the articulating surface of theimplant corresponds to a simulated healthy articulating surfacereconstructed from a 3D model based on one or more images taken with MRIor CT-scanning of the damaged articulating surface in which the implantis to be placed in a recess. 6: The method according to claim 1, furthercomprising: designing the shape and size of the implant dependent on thesize and shape of the damage in the articulating surface and dependenton the curvature of the simulated healthy contour of the articulatingsurface in the area substantially coinciding with the damage; anddesigning the positioning mark to point out the same direction, or jointaxis, as at least one of a mark made, or to be made, on the side of arecess in a damaged articulating surface of a joint and a positioningmark on a guide tool to be used for facilitating placement of saidimplant in the recess. 7: An implant designed using the design methodaccording to claim
 1. 8: A method for inserting an implant in a joint,comprising: providing an implant having at least one positioning mark,wherein said at least one positioning mark is positionally adapted onthe surface of the implant to be visible for detection by a visionsystem; detecting, by the vision system, said at least one positioningmark in relation to at least one of at least one mark made on the sideof a recess made in the articulating surface of the joint and at leastone pre-determined anatomic dependent direction; and inserting theimplant in the recess by directing the at least one implant positioningmark in a direction dependent on the direction of at least one of atleast one mark made on the side of a recess made in the articulatingsurface of the joint and at least one pre-determined anatomic dependentdirection, wherein said inserting is aided by said detecting by thevision system. 9: The method for inserting an implant in a jointaccording to claim 8, wherein said detecting by said vision systemcomprises detecting an implant positioning mark on the articulatingsurface of one substantially circular shape among at least two partlyoverlapping substantially circular shapes of said implant. 10: Themethod for inserting an implant in a joint according to claim 8, furthercomprising: inserting the implant in the recess by directing the atleast one implant positioning mark in the direction of at least one ofat least one mark made on the side of the recess on the articulatingsurface. 11: The method for inserting an implant in a joint according toclaim 8, further comprising: making a recess, by one of a surgeon and amechanical arm such as a robot arm, in an articulating surface of thejoint where the implant is to be inserted; and making a mark, by one ofa surgeon and a mechanical arm such as a robot arm, on an articulatingsurface on a side of said recess on the articulating surface. 12: Themethod for inserting an implant in a joint according to claim 8, furthercomprising: providing a guide tool comprising a positioningfeature/mark; and making, by one of a surgeon and a mechanical arm suchas a robot arm, a mark on the side of a recess made in an articulatingsurface of the joint in the direction of the positioning mark of saidguide tool, thereby determining the future placement orientation of theimplant. 13: A method for inserting an implant in a joint, comprising:providing an implant having at least one positioning mark, wherein saidat least one positioning mark is located on the surface of the implantto be visible for detection; providing a storage unit, e.g. a box, forstoring an implant prior to inserting the implant in a recess of a humanjoint, wherein said storage unit comprises at least one of a mechanicalrecess structure and/or holding means adapted for positioning theimplant in a rotationally fixed position in the storage unit, andwherein said storage unit further comprises at least one referencefeature; detecting said at least one positioning mark in relation tosaid at least one reference feature; and placing the implant in thestorage unit by directing the at least one implant positioning mark onthe surface of the implant in a specific, e.g. pre-determined,rotational direction in relation to said at least one reference featureof the storage unit, gripping the implant in the storage unit, whereinthe implant is rotationally oriented in accordance with said specificrotational direction of the at least one implant positioning mark inrelation to said at least one reference feature of the storage unit,removing the implant from the storage unit, wherein the implant isrotationally oriented in accordance with said specific rotationaldirection of the at least one implant positioning mark in relation tosaid at least one reference feature of the storage unit when removedfrom the storage unit, and inserting the implant in a recess made in ahuman joint in a correct placement orientation, wherein said correctplacement orientation is determined by how the implant is rotationallypositioned in said storage unit in relation to said at least onereference feature of the storage unit. 14-20. (canceled)